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Full text of "Fourteenth national potato utilization conference report : held at Yakima, Washington, July 20-22, 1964"

Historic, archived document 

Do not assume content reflects current 
scientific knowledge, policies, or practices. 



4 




ARS-74-30 



fourteenth nation a4.2.;s55 
potato utilization "^^^^^ 
conVerence report 



HELD AT YAKIMA, 
WASHINGTON 
JULY 20-22, 1964 




AGRICULTURAL RESEARCH SERVICE, 
U.S. DEPARTMENT OF AGRICULTURE 



THE FOURTEENTH National Potato Utilization Conference was 
held July 20- Z2, 1964, in Yakima, Washington. This report contains 
the texts of the speeches presented. 

These annual conferences continue to make results of current 
research and development available to the potato industry, particularly 
in the fields of production,marketing, and industrial utilization. Growers, 
shippers, processors, and research and extension workers in State and 
Federal agencies attend. Although they are called national meetings, 
they attract attention in other countries. Canada is always well repre- 
sented. This year men from three European countries were present. 

The United Fresh Fruit and Vegetable Association and the Western 
and Eastern Utilization Research and Development Divisions of the U, S. 
Department of Agriculture have provided continuing sponsorship of the 
conferences over the years. Local growers' groups, State and Federal 
scientists, and industrial organizations all contribute, particularly in the 
region selected for each annual conference. 

Washington State University was host for the conference reported 
here. In his introductory remarks, which are included in this report, 
Dr. M. T. Buchanan, Director of the Washington Agricultural Experi- 
ment Stations, mentions those who cooperated in making arrangements and 
contributed in other ways to the success of the conference. 

The Fifteenth National Potato Utilization Conference will be held 
at East Grand Forks, Minnesota, in July, 1965. 

Copies of this report, prepared by the Western Utilization 
Research and Development Division, , Agricultural Research Service, 
USDA, are available from Western Regional Research Laboratory, 
Albany, Calif or nia, 94710, headquarters of the Division. 



November, 1964 



CONTENTS 

Page 



Introductory Remarks, M. T. Buchanan - -- -- -- -- -- -- -- -- -- 3 

Introduction: Panel on"Potatoes, Fresh and Processed, ajid the Consumer, " 

Kris Bemis - -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- - 5 

Economics of Potato Utilization, Robert E. Olson - -- -- -- -- -- -- - |2 

Industry Outlook for Fresh Potatoes and for Processed Potato Products, 

A. E. Mercker ___-__-_-._>----_ 

Washington Potatoes for Processing: Chips, Stews, Salads, Paul Hackstadt " 21 
Quality Requirements of Potatoes for Processing: Frozen Products, C. R. 

Miller 23 

Grower-Processor Relationships, Donald B. Robertson - -- -- -- -- -- 27 

Potato Utilization in Canada, F. H. Hatfield ---------------- 30 

The Red River Valley Potato Processing Laboratory, Roy L. Shaw, Jr. - - - 34 

The Aberdeen Potato Research Center, George W. Woodbury - -- -- -- - 35 

Evaluation of Potato Varieties for the Sloughing and Translucency of Dice 

Following Freezing During Processing, C. E. Cunningham, R. V. 

Akeley, and T. E. Snyder 33 

Stability of Frozen French Fries at Refrigerator Temperatures, Frank P. 

Boyle, George K. Notter, H. David Michener and D. G. Guadagni - - - - 38 

Oxidative and Off-Flavor Development in Potato Granules, B. Feinberg - - - 39 
Quick- Cooking Dehydrated Potato Pieces by Explosive Puffing, Roderick 

K. Eskew 41 

Studies on the Relationship of Specific Gravity to Total Solids of Potatoes, 

W. L. Porter, T. J. Fj.tzpatrick and E. A. Talley - -- -- -- -- -- - 45 

Biochemical Factors Involved in Potato Black Spot, F. D. Howard, H. Timm, 

M. Yamaguchi, and D. L. Hughes - -- -- -- -- -- -- -- -- -- - 45 

Bruising and Temperature in Relation to Internal Discoloration of Potatoes, 

M. L. Weaver - -- -- -- -- -- -- -- -- -- -- -- -- -- -- - 52 

Factors Affecting Sloughing of Potato Tissue, Mary V. Zaehringer, Helen 

H. Cunningham, and Duane Le Tourneau - -- -- -- -- -- -- -- -- 54 

Effects of Storage Temperatures of Red River Valley Potatoes on Flake 

Quality, Nicholas Sandar, A. M. Cooley, and L. A. Schaper - -- -- -- 58 

Improving Firmness and Texture of French Fried Potatoes, Ora Smith and 

C. O. Davis- 65 

Advertising of Fresh & Processed Potatoes by Food Stores, John H. Weber - 67 

Radiation Sprout Inhibition of Potatoes, Fred Heiligman - -- -- -- -- -- 70 

Accomplishments of Potato Research in Washington - -- -- -- -- -- -- 73 

Blackspot: Robert Kunkel and Cooperators - -- -- -- -- -- -- -- - 73 

Potato Diseases: W. G. Hoyman - -- -- -- -- -- -- -- -- -- -- 74 

Potato Handling and Shipping Studies: Merle Weaver _____ 75 

Potato Insect Control: B. J. Landis _------------------ 78 

Problems of the Potato Industry in the Columbia Basin Which Need 

Further Research - -- -- -- -- -- -- -- -- -- -- -- -- -- 80 

A ttendants ___________-__-____-__--------- 81 



INTRODUCTORY REMARKS 



M. T. Buchanan, Director 
Agricultural Experiment Stations, Washington State University 

It is my privilege and pleasure to help open this cd'nference and to serve 
temporarily as your Chairman. We are proud to have the 14th National Potato 
Utilization Conference convene in Yakima, Washington, This conference in the 
State of Washington was a long-time objective of our recent Chairman of Horticulture, 
Dr. T. A. Merrill, whose untimely death prevented him from being Washington State 
University's host representative. Dr. Merrill's involvement in potato research was 
long-standing. Last summer he attended the 13th National Potato Utilization Con- 
ference at Riverhead, New York, in preparation for this conference. He was to have 
been this year's general chairman. He did much of the work on the early planning, 
including a meeting with the planning committee in December, 1963, in Washington, 
D. C. He wanted those attending to see not only our potato industry but some of 
Washington's scenic areas as well. We hope yoa take time to do so. 

As you see on your program, this conference is sponsored by the United Fresh 
Fruit and Vegetable Association (Potato Division), the USDA and several Washington 
State organizations: Washington State Potato &: Onion Shippers Association, Washington 
State Potato Commission, and Washington State University. 

Much credit is due numerous folks who had a part in making arrangements. 
After Dr. Merrill's death. Dr. I. C. Feustel of Federal Extension Service took over 
many of the responsibilities and served as program chairman. Don Bakes, Agri- 
cultural Extension Service, WSU, planned the Columbia Basin tour that I'm sure you 
will enjoy very much. Fred L, Ramsey of the Washington State Potato Commission, 
Don E. Trimble of the Washington State Potato and Onion Shippers Association, and 
John Keene of WSU's Agricultural Extension Service have helped with the plans for 
the tour and local arrangements. Registration has been through the Yakima Visitors 
and Convention Bureau. And, as in most organizations, the former Chairman, 
Dr. Merrill, had a good, "right arm, " Dr. William B. Ackley, who has taken over 
both as Chairman of Horticulture at WST''' and as general chairman of this conference. 
We are pleased with his performance and prospects. 

Before I introduce others who are to make introductory remarks may I make 
a couple of comments about potato production and potato research in Washington 
State. Potato production in Washington doubled with the development of the Columbia 
Basin Project. While our yields are among the highest, if not the highest, in the 
country our growers have had numerous problems. It has been a pleasure to be 
associated with the research program which has evolved in response. It has been a 
cooperative program of the highest order. Financing has come from the potato 
industry via the Washington Potato Commission, from the Washington State Depart- 
ment of Agriculture, from WSU's Agricultural Experiment Stations, and from USDA. 
All have participated in research program planning activities. Most of the produc- 
tion research work itself has been done by USDA and Experiment Station personnel 
and you will have a chance to learn more of this on your tour. An account of the 
projects will be included in the report of this conference. Dr. W. D. Maclay also 
will give you a report very shortly on recent developments in USDA utilization 
research. 



3 



I want to compliment the potato industry on its support of research. As I 
mentioned earlier, we are especially proud here in Washington of the Washington 
State Potato Commission's efforts in that direction. Mr. Ramsey can give details 
to any of you who are interested. 

c 

May I now introduce two co-sponsors for further introductory remarks: 
Mr. Joe Dwyer, Director, Washington State Department of Agriculture, and Dr. 
M. J. Copley, Director, Western Utilization Research and Development Division, 
Agricultural Research Service. (Because of space limitations these introductory 
remarks and those of Dr. W. D. Maclay are omitted. ) 



Potato research of the Institute of Agricultural Sciences 
Washington State University is conducted cooperatively with 
the Washington State Potato Commission, the State Department 
of Agriculture and the U. S. Department of Agriculture. During 
the tour of the Columbia River Basin on July Zl, attendants at 
the conference saw many of the experimental plots and heard 
explanations of the projects. Summaries of accomplishments of 
this cooperative program will be found on pages 73 to 80. 



4 



INTRODUCTION: PANEL ON "POTATOES, FRESH AND PROCESSED, 

AND THE CONSUMER" 



Kris Bemis 

United Fresh Fruit and Vegetable Association, Washington, D. C. 

The subject for this panel and the four distinguished participants in it have 
been carefully chosen, with a purpose. I can best explain it by suggesting that you 
take a backward glance with me at the first of these conferences and the changes 
that have occurred since then. 

We organized the First National Potato Utilization Conference in 1948 in the 
wake of overproduction resulting from Government price support. National maga- 
zines then called it "The Great Potato Scandal. " The primary purpose was to 
think up and develop ways to utilize this indispensable crop constructively and to 
restore its stature in the public mind. 

It's a little hard to realize that potato processing in those days consisted 
mainly of making starch and alcohol, although our friends the chippers were repre- 
sented at that first conference and they were beginning to become larger potato users. 
Their fine trade association, the Potato Chip Institute International, was then 11 years 
old but was really just getting under way. We can congratulate them on their 27th 
Anniversary celebrated this year. But other processing developments were practi- 
cally in their infancy. 

To visualize how potato processing has grown, let's make a simple com- 
parison. The Government Crop Reporting Board began publishing utilization figures 
with the 1956 crop. In that year the fresh market took 86 sacks of potatoes out of 
every 100 that were sold; the processors took the other 14. Of the 196Z crop, the 
latest for which we have figures, the fresh market took 73 sacks; the processors Z7. 

In still another comparison, where the chipper bought 14 sacks of potatoes in 
1956, he was buying 24 in 1962. For every 3 sacks the dehydrator bought in the 
former year, he was buying 9, and the freezer had jumped his 1956 purchase of 4 
sacks to 18 sacks. The canner had not made such a large increase but had more than 
held his own. The processors who, as a group, bought 24 sacks of potatoes in 1956 
were buying 54 sacks in 1962. 

I saw reliable figures recently which listed 50 different items of processed 
potato products for sale today. You will see them all on supermarket shelves, but 
perhaps you will agree with those of us in the fresh industry in our viewpoint. I 
think even our good friends the processors would admit that they spend their days 
and nights striving to maintain the quality their product had when it was fresh. We 
have to admit that in some cases they have succeeded remarkedly well. Perhaps 
we can leave our friends the chippers out of this, for they are really supplying 
consumers with a different product, and doing remarkedly well at it. 

We have to admit that the freezer, the dehydrator, and to some extent the 
canner have taken the play away from fresh potatoes. They provide convenience 
plus a certain uniformity of quality. Almost without exception we can buy their 
product and find that it has the same quality we bought last week or last month. 

5 



I think that in a large degree we have permitted this to happen by default. We have 
heard enough in these meetings and recorded enough in our proceedings about specific 
gravity grading, storage problems, and shipping and handling practices to have 
maintained or even improved our fresh product if we had worked as hard at it as the 
processors did with their problems. 

The fact still remains that the fresh potato at harvest time, properly grown, 
stands at the peak of quality and desirability. In its route from that point to the 
consumer, its deterioration will be fast or slow depending on the knowledge and 
skill with which it is handled. You may have observed from recent market reports 
that the consumer has been willing to pay an unusually high price for fresh potatoes 
for the past month or so. There was of course a decrease in the estimated supply, 
but this supply for the most part was coming from shipping areas that were blessed 
with good quality and were well organized with centralized warehousing, grading, 
and packing. There is still, we believe, a broad market for the fresh product, and 
that brings me to the members of this panel. 

They represent a cross section of the distribution system and the consumers. 
We present a hom e e conomist from a leading university who knows the viewpoint of 
the housewife. We have a service wholesaler who is a leader in produce merchandis- 
ing in the Southwest. It's part of his everyday work to help retailers to sell potatoes 
as an important item in the produce department. His firm distributes some 3, 000 
carlots of fresh fruits and vegetables annually. 

Then we have a retailer who as a grocery merchandiser lives with potatoes 
in terms of packaging, sales appeal, consumer complaints, and other factors. And 
we have from the public feeding industry an outstanding restaurant operator who has 
achieved national recognition as an exponent of salesmanship in the art of "dining 
out. " From them we shall hear about the potato as a food in today's world - its 
advantages and its shortcomings. 

D r. Mary Zaehringer is Head of the Department of Home Economics Research 
at the University of Idaho, Her state leads in the production of dehydrated and frozen 
potato products and she has tested a number of them in her laboratory, Virgil 
Campbell is Grocery Merchandiser for Fred Meyer, Inc. of Portland, Oregon. His 
firm is a shipper as well as retailer and he lives every day with the problems of 
produce packaging, sales appeal, introduction and promotion of new products, profit 
margins, and consumer complaints. Bill Romney is the Central Merchandise 
Director of the Romney Produce Company of Phoenix, Arizona, with branches in 
Albuquerque and El Paso. The latter town is Bill's headquarters. He is a member 
of the United Merchandising and Management Board and a front runner in wholesaling 
fresh fruits and vegetables. His firm maintains a buying office in Los Angeles, it 
has established a central produce packaging service, has a recognized brand name, 
and conducts produce schools for retailers. His annual volume exceeds 3, 000 car- 
lots of fresh fruits and vegetables. Larry Hilaire is the well known owner and 
operator of Hilaire's Encore Restaurant in Portland, Oregon. He is known in the 
public feeding industry as an outstanding booster and his associates in the business 
honored him in 1957 with the presidency of the National Restaurant Association. 



6 



Dr. Mary V. Zaehringer, University of Idaho : The homemaker likes 
potatoes. Both fresh and processed have a place in her food plan. She likes the con- 
venience of processed potatoes and the standard quality of the product. She likes the 
uniformity of size in packaged fresh potatoes but is very distressed if fresh potatoes 
contain black spots, especially black heart. The consumer also dislikes having fresh 
potatoes fall apart on cooking -- that is, to "slough. " Perhaps packages should in- 
dicate the best method of cooking for the potatoes packaged. 

Prior to this meeting we served 12 different processed potato products pre- 
pared according to directions on the packages to a panel of trained judges who scored 
them for odor, color, texture, flavor, acceptability, and size of serving as stated on 
the package. In general the products were quite good. The flavor of products browned 
with butter was especially well liked. The judges preferred a mealy inside texture 
but wanted a crisp, tender outer crust. "Soft" crusts were scored down. In certain 
products, some judges objected to onion or other added flavors, but on the whole they 
were considered acceptable or even very good. 

The instant mashed products were considered "acceptable" to "very good" but 
texture was not always optimum. Opinions on the flavor of scalloped, au gratin, and 
canned German potato salad varied. Some wanted more onion, some less. Some 
wanted more cheese, some less. But the texture, odor, and acceptability were good. 

One comment I would like to make on processed products is that some packers 
are overly optimistic in estimating the number of servings in the package. In one- 
third of the products tested, the size of serving was considered to be too small. 

As a home economist I am also concerned with the retention of the nutritive 
value of processed products, especially ascorbic acid. Most nutritional surveys have 
shown that American diets are apt to be deficient in this vitamin, I believe all 
nutrients in basic foods such as the potato should be conserved - -so far as possible -- 
in all processed foods such as processed potatoes, TV dinners, etc. If processing 
removes important amounts of nutrients they should be added back just as flour is 
enriched. However, I do not believe that the average homemaker is as concerned 
about nutritional value of processed and instant foods as I think she should be. 
Moreover some are mistaken about the number of calories in potatoes. One medium- 
sized potato carries only about 100 calories and these calories carry with them many 
important nutrients. 

I would also like to make one final comment as a consumer of potatoes in 
restaurants. I believe that potatoes baked in foil are definitely not at their best. 
They are not light and fluffy as a baked potato should be and I wish that all restaurants 
would bake them in their jackets without foil in order to serve a mealy, fluffy product. 

"Virgil Campbell, Grocery and Delicatessen Merchandiser, Fred Meyer, Inc. , 
Portland, Oregon: All of us have axes to grind -- and the retailer is no different 
from anyone else. Even though I am more than 50 miles from home, and therefore 
qualify as an "expert" by the distance definition, I am still a retailer with an ax to be 
ground. 

The retailer has his aims and his standards. Among the several thousands of 
products in his store, some contribute much more to his success than others. He's 

7 



got to solve his own problems and help others solve theirs. 

When a retailer looks at the merchandising problems of a large-volume food 
commodity like fresh potatoes, he realizes of course that his standards and aims are 
really not greatly different from those of the producer, wholesaler, and consumer. 

Here are some standards that a retailer uses in judging commodities. He 
likes to sell products (1) that move in large volume, (2) that have mass appeal, (3)that 
are consumed quickly, (4) that make an attractive pack,(5) that are consistent in 
quality, (6) that are low in handling cost, (7) that shrink very little while they are in 
his possession, (8) that are clean and healthful, (9) that create consumer satisfac- 
tion, and (10) that sell with adequate mark-up in price. 

Now how do fresh potatoes rank on each of these ten points? On several they 
rank well but on others they leave something to be desired. Consumers tell us that 
they want all-purpose potatoes that are uniform in size. They want help in learning 
new and better ways to prepare potatoes. Actually the average housewife is not as 
accomplished in kitchen science as she may think she is. She is constantly tempted 
by alternative food products that have been processed and neatly packaged with 
directions for use. 

Although we have grades in potatoes few consumers know what a No. 1 grade 
of potato is because little educational effort is made. From casual observation No. 1 
spuds include cuts, bruises, nonuniform shapes and sizes and even some internal 
discolorations. Handy carrying packages are supplied for some foods, but the con- 
sumer's potato package has been the same over many years. And so opportu- 
nity would seem to lie in the direction of better and more uniform packs, more 
consistently good quality, better grading, more education on preparation, and more 
public information on food values. 

Speaking as a retailer I'm sure that the way is open to more cooperative 
effort in the directions I have indicated. 

W. F. Romney, Romney Produce Company, Phoenix, Arizona : . In the mer- 
chandising of any "fresh" commodity to the consumer, the first qualification is 
"quality. " In my firm we are service wholesalers, concerned only with the sale of 
"fresh" product. We must be greatly concerned with the "quality" we sell. 

During the last three years our company has promoted a brand name. Our 
slogan, which accompanies our red and gold diamond and all advertising is "The 
Mark of Quality". Thus, we are determined to keep quality uppermost in the minds 
of those who purchase and consume our product. Quality control should be foremost 
at all levels of the potato industry: at the grower-shipper level, the service- 
wholesaler or distributor level, and also the retail level. 

If the industry is to compete with others which are trying to replace potatoes 
in the daily diet, we must all be concerned with better quality. And for fresh sales 
this is imperative, for only when we have a potato of the highest quality can we 
educate the consumer to use more fresh potatoes. 



8 



Education by use of recipes or direct teaching such as cooking schools is a 
must, especially with our growing number of young marriages. Many young women 
have never been exposed to the kitchen arts, either at home or at school, since many 
of our states do not require or even offer courses in home economics. For those of 
us in the "fresh" field there is a vast opportunity to educate the consumer to use fresh 
potatoes, especially when processors are making so many ready-made products that 
you can "just heat and eat. " 

The consumer needs to be made aware of the many varieties, grades, and 
sizes of potatoes. As an example, until a very few short years ago, in our part of 
the country, many consumers did not realize that potatoes need not be between 8 and 
12 ounces to be U. S. No. 1 grade or that a "B" size could still be a U. S. No. 1 grade. 
There is a sale for all sizes and varieties if the consumer is made aware of the dif- 
ferences and uses of each. No one, not the grower, shipper, wholesaler or retailer, 
can force consumers to buy what you want them to buy. There is no one variety of 
potato nor any one size nor any one size of package that will suit the tastes or size 
of family of all consumers. 

Therefore, we must do a job of merchandising and give the consumers what 
they want. In our own particular operation we offer Mrs. Consumer nine sizes of 
packages in each variety of potatoes that we sell. These include four 10-ounce bakers 
in a tray overwrapped with shrinkable polyethylene film, a 2-lb. poly bag of pre-cut 
crinkle- cut French fries, a 2-lb. poly bag of regular pre-cut French fries, a 2-lb. 
poly bag of whole peeled, a 5-lb. , a 10-lb. , a 20-lb. , and a 25-lb. poly bag, and a 
50-lb. carton. These are all in addition to the 100-lb. sack for sale in bulk over the 
counter. Also in the 50-lb. carton and 100-lb. bag we offer 4 different size ranges 
of selected baker potatoes: 6-8 oz. , 8-10 oz, , 10-12 oz. , and 6-14 oz. , besides a 
regular U. S. No. 1 and U. S. No. 2 graded potato. In the U. S. No. 2 grade we 
offer the 10-lb., 20-lb,, and 25-lb. poly bags. While not every retail store we 
service handles every one of these sizes, they are available and it takes all of these 
sizes to satisfy the needs of all of our customers. 

Sale of the different sizes of packages varies with the different neighborhoods 
in any given city or town. In the apartment section the families are small and the 
poly-wrapped trays of bakers and the 5-lb. poly bag are the popular sellers. In 
most other parts of the city the 10-lb. poly bag is the most popular and in sections 
where larger families prevail the larger sizes take over in popularity and movement. 
From this you can readily see that just to sell one commodity, such as potatoes, soon 
becomes a rather complicated process. 

While the individual consumer is important, let us not overlook the tremendous 
potential of sales to institutions. In our particular sales areas and I'm sure all over 
the nation, institutions such as hospitals, schools, restaurants and any other public 
food services are each year becoming larger consumers of foods. To keep up with 
and stay ahead of the freezers and processors we offer our institutional customers 
a large selection of fresh potatoes: 25-lb, poly bags of pre-peeled whole, regular 
French fries or crinkle-cut French fries in addition to the before-mentioned 2-oz. 
size gradation in the 100-lb. sack and the 50-lb. carton -- also a pre-washed foil- 
wrapped baker. In our El Paso, Texas, branch we have one customer who buys 
nothing but 16-oz. Russet bakers for his steak house. To this customer, and most of 
our customers, price is not the object but rather quality of product and service. 



9 



To aid our retail and institutional outlets to sell more fresh potatoes as well 
as all other fresh fruits and vegetables, we offer merchandising aids in various 
forms. For the retailer we offer schools to train store management as well as 
produce men in how to better prepare, handle and sell the fresh product. We use 
merchandisers trained by the United Merchandising Institute of the United Fresh 
Fruit and Vegetable Association to work in these retail outlets, not to do the work 
of the retail produce men but to train them in methods of merchandising, such as 
proper use of handling and preparation equipment, more efficient designs of back 
room and selling areas, types of handling and refrigeration equipment best suited 
for each operation, effective methods of display and how and where to use mass and 
promotional displays, use of point-of-sale advertising materials, how to use related 
items for tie-in sales, and proper placement of commodities to generate greatest 
customer appeal and acceptance. We help them plan, design, and execute promo- 
tional sales. Sampling demonstrations with recipes are carried out at the retail 
level. These are usually used in conjunction with a promotional sale. 

To institutions we offer recipes set up especially for quantity and designed to 
use the fresh product. We work closely with the restaurant associations in the 
various states to promote and encourage better operational procedures. Any help 
we offer is designed to teach or to change the thinking and work habits of the retail 
or institutional personnel, so that they may do their job better and continue to have 
interest and pride in the satisfaction of a job well done. 

Our educational program is carried to the consumer through television, 
radio, and newspapers. While the company does not maintain a regular advertising 
schedule through these channels we work very closely with the County Extension 
services and make guest appearances on television and radio and furnish market 
and supply reports along with other educational materials for use in the newspapers. 
Our merchandisers conduct schools on buying fresh produce and on cooking to show 
Mrs. Consumer how to use "fresh. " These schools are conducted for service clubs, 
women's organizations and secondary and elementary school classes. Educational 
films and printed materials on the growing, harvesting, shipping, distribution and 
sales, as well as nutrition, cooking methods, and recipes are designed to appeal to 
the various age groups involved in the various schools. 

The need for better understanding and education of the consumer in all phases 
of the "fresh" produce industry is the responsibility of all of us who are in any way 
concerned with "fresh" produce, so that they will know what is meant when we of the 
industry say "fresh is best --fresh for health. " 

Larry Hilaire, Encore Restaurant, Portland, Oregon : As one who has spent 
many years in the restaurant industry and has tried to develop a truly professional 
interest in it, I of course miss no opportunity to tell the public about restaurants. 

It is the fourth largest industry in the United States. It uses 30 percent of 
our agricultural products, 85 percent of the prime beef, and 75 percent of our finest 
fresh fruits and vegetables. Our restaurants serve many millions of meals each 
day and gross in a neighborhood of $20 billion per year. A major problem is cost 
of labor. Average profit is under 2 percent. Therefore we are willing to pay a 
premium for products with built-in labor. Each item that is easily converted saves 
us labor time and money. 



10 



I have participated in counseling with other industries and have also served as 
President of the National Restaurant Association, From this activity ana my own 
experience I know of course that my industry wishes to contribute to better living, 
wishes to help people learn how to eat out, how to eat with each other, how to 
experience excellence in food as in other phases of living. We live in an age of 
increasing leisure, increasing mobility, increasing need for relaxation. If we fully 
realize this opportunity we will feel inspired to cooperate in meeting it successfully. 

Now I know that 1 am speaking to one of the largest of the food industries and 
I want to shock you with some facts. As an industry you seem to fail to realize the 
potentials of potatoes and do not really take advantage of the large restaurant market. 

Food service managers want fine potato products -- graded, sized, scrubbed, 
oiled, peeled, sometimes quartered, or sliced, diced, Frenched, or chipped, hashed, 
grated or otherwise prepared. We are an excellent market for a great variety of 
potato products but frankly, to get them, we must do an enormous amount of 
searching, improvising, and scrounging around in order to find good products and 
new ideas. Everyone is looking for variety. Everyone is looking for excellent 
quality. 

But do we get any help from the potato industry itself? My answer is that we 
get very little help indeed. In my own business I spend many evening hours searching 
through trade and home magazines for new ideas. Few of those I use come from 
enterprising representatives of potato production and marketing. 

Some of course come from processors and we do use flakes, granules, and 
frozen products of all kinds -- but let me ask. How frequently have we been con- 
sulted on the development of new products? 

Women obtain many home food preparation ideas from restaurants. Here is 
a major reason for cooperation of the potato industry with restaurants. I could go 
on indefinitely with examples and of course I would enjoy doing so, because I enjoy 
contacts with industries related to mine. But let me emphasize that we have much 
to look forward to -- many new and interesting developments lie in the future of 
potatoes. 



11 



ECONOMICS OF POTATO UTILIZATION 



Robert E. Olson 
Economic Research Service, USDA, Washington, D. C. 

In recent years the potato industry has been affected by a number of signifi- 
cant changes related to value and utilization of potatoes. These changes include 
specialization and concentration of potato production, development and growth of new 
processed products, growth of population and income, and intensified sales promotion 
and advertising. Use of potatoes may gain about 25 percent by 1975 but gains in out- 
put and consumption of the processed forms should be considerably more. 

The story is well known of how highly productive commercial potato areas 
have come to the fore. However, how changes are interrelated with changes in 
marketing practices and in marketing efficiency is not as widely appreciated because 
of the dynamic changes in the economy that obscure direct indications of efficiency. 

Public interest in food marketing is at a high level today. Consumers spend 
more than $65 billion a year for food that originates on American farms. The total 
bill for marketing is now about $45 billion. Services in marketing have increased 
considerably during the past decade and so has their cost. Their rise in cost has 
been moderated by increases in output per man-hour in food processing and distribu- 
tion. Consumer incomes have also risen greatly but consumer expenditures for food 
have not risen nearly as fast as consumer income. Consumers spent 19 percent of 
their disposable income for food compared with 23 percent in 1952. 

But, have not marketing charges risen because of added services so as to 
permanently change the average proportion of the consumer's dollar for the farmer? 
Our figures show they probably have, but not as much as is sometimes implied. 
The results of the current study by the Bureau of Labor Statistics will enable a 
better measure of current levels of food expenditures. 

Much of the cost of marketing is not directly related to prices of farm 
commodities nor does it vary much with small changes in volume in the short run. 
Labor costs make up about 48 percent of the marketing bill; transportation, 
10 percent; corporate profits before taxes, 5 percent; and other costs, 37 percent. 
The principal items among the other costs in approximate order of relative impor- 
tance are containers and packaging, advertising, depreciation, taxes other than 
Federal income taxes, rent, repairs, and interest. 

Since a large part of the activity in marketing occurs near the consumer, its 
costs are influenced by the same variables that influence the income of urban con- 
sumers. Retailing accounts for roughly one-third of the marketing bill, processing 
one-third and transportation, assembly, and wholesaling for the rest. 

The hourly earnings of workers in the food marketing industries have followed 
the general trend in wages. But labor cost also depends on output per man-hour as 
well as hourly earnings. In recent years increased output per man-hour has kept 
labor costs per unit of food marketed from rising as much as hourly earnings. The 
annual rate of growth in output per man-hour worked by employees in factories 



12 



processing farm food products averaged 2.9 percent from 1947 to I960. This is about 
the same as the rate for the total private nonfarm sector which includes manufacturing, 
trade, and service industries. Likewise, sales per man-hour in retail food stores 
increased by more than 35 percent between 1948 and 1958. 

Growth in output per man-hour in food marketing is close to the average for 
the nonfarm economy. Such a result should be surprising, for food marketing is a 
large sector with great diversity of operations. Aggregate labor cost in marketing 
depends chiefly on the quantity of services rendered and the level of wages and 
productivity in the nonfarm sectors. 

The cost of transportation service is of major importance in marketing farm 
products, especially potatoes. Contrary to the trend for most costs, some rates for 
transporting farm products have been reduced in the last few years. The transporta- 
tion industry is ];iow in an era of considerable changes in technology, regulatory 
approach, and increased competition between alternative modes. 

Not all increases in services necessarily increase the cost to the consumer. 
For example, studies have shown the extra cost of processing and packaging may be 
offset by reduction in waste and spoilage and lower cost of shipping and handling. 
Some services in our marketing system have been reduced or eliminated, such as 
credit and home delivery. The average marketing services associated with a unit 
of food have increased by 30 percent since 1940. Total services have nearly doubled 
in the same period because services per unit have increased, and the quantity of 
farm food marketing has grown by more than 50 percent. 

The impact of added services in marketing varies by commodity, production 
region, supply- demand relationship , and other factors. These points were brought 
out in a study of marketing potatoes, snap beans, oranges, and lemons with variations 
in services. (Henry T, Badger, "The Impact of Technological Change on Marketing 
Costs and Growers' Returns--Case Studies for Potatoes, Snap Beans, Oranges, and 
Lemons, " Marketing Research Report 573.) 

Census figures show that the number of plants processing farm foods declined 
about 10 percent between 1947 and 1958, (E. W. Bunkers and Willard W, Cochrane, 
"On the Income Elasticity of Food Services, " Review of Economics and Statistics, 
May 1957, pp. Zll-217.) Thus fewer firms are purchasing for processing. On the 
other hand, processing provides new outlets and is often most attractive to growers 
in areas of concentrated commercial production. In the postwar period an added 
dollar of consumer income added 13.9 cents to food expenditures, 10, 3 cents to the 
marketing bill, 1.1 cents to cost of nonfarm services, and 2. 5 cents to net returns 
to farmers. 

Convenience foods . The increased number and variety of food products 
available in different forms on grocery shelves today not only expands consumer 
choice but also has made it more difficult for consumers to tell whether or not 
convenience foods cost more than less highly processed foods. People can choose 
among select foods in several stages of preparation from basic separate ingredients 
for home-prepared foods to those prepared by food manufacturers ready for con- 
sumption. The cost of convenience foods bought in an average purchase pattern was 
compared with the cost of an equal number of servings of fresh or home - prepared. 



13 



Our study shows that convenience foods produced from U. S. farm com- 
modities accounted for $12. 55 or 90 percent of the $14. 03 spent for convenience foods 
in a $100 purchase at grocery stores. The remaining $1.48 was spent for coffee, tea, 
fish, and shellfish. Many of the foods included in the other $85. 97 spent for all other 
foods purchased in grocery stores have convenience features but no comparable 
counterpart. Some examples of the foods in this group are whole milk, lettuce, fats 
and oils, and steaks. 

As a group, the convenience foods produced from U. S. farm commodities 
differed little from their home-prepared counterparts in cost. There was consider- 
able variation within the group, however. For instance, the quantities of convenience 
forms of baked products, desserts, and candies included in the $100 food purchases 
cost $0. 54 more than their home-prepared counterparts, a difference of 46 percent, 
while at the other extreme processed fruits and vegetables cost $1. 64, or 40 percent, 
less than their home-prepared counterparts. 

Comparing all convenience foods studied with their fresh or home-prepared 
counterparts shows that use of the convenience forms resulted in a saving of $1. 07 
per $100 of food purchased. Convenience forms of U. S. farm products in the 
purchase pattern accounted for Z7 cents of this saving, and the convenience products 
from other sources for 80 cents. 

In terms of individual items, however, almost three-fourths of the 158 
convenience foods studied were more expensive than their less highly processed 
counterparts. In addition to convenience, major reasons for processing are 
storability and economy of transport. Big sellers among convenience foods are 
usually as economical as handy. 

We have compared the costs per serving of 8 processed potato products with 
costs per serving of their fresh counterparts. The products compared were frozen 
French fries, frozen potato puffs, frozen potato patties, dehydrated scalloped 
potatoes, dehydrated hash browned potatoes, and canned whole white potatoes. For 
each of the 8 potato products compared, the cost per serving of the processed 
product exceeded the cost per serving of the fresh counterpart. Cost of frozen French 
fries, a relatively high-volume item, averaged 6 percent more than cost of home- 
prepared French fries. 

The influence of price and income. Changes in per capita consumption of any 
food reflect economic influences as well as many socio-economic factors. Economic 
influences expected to affect the consumption of processed potatoes are price, 
consumer incomes, tastes and preferences, and prices and availability of substitutes. 
Important socio-economic influences include size of household, nationality origin, 
occupation of head of household, and urban versus farm residence. 

Only broad generalizations can be made as to the effect of price and income^ if 
any, upon processed potato consumption as these other demand factors that cannot 
be shown directly also influence consumption. In addition, improving technology and 
development of new products has resulted in increased output, wider distribution, 
greater availability, and stepped-up promotion of processed items. 



14 



A study shows that retail prices of processed potatoes in constant dollars, as 
represented by prices of frozen French fries, declined about 2 percent per year during 
1956-61. During the same period, the annual average increase in consumption of 
processed potato products was about 19 percent and for frozen French fries, 47 per- 
cent. The changes in per capita consumption of frozen French fries are considerably 
greater than expected from the changes in prices. 

Consumer disposable income during the 6-year period studied increased at an 
average rate of 1. 2 percent per year. However, this increase in income along with 
the decrease in price still falls short of explaining the large increase in consumption 
of processed potato items. The failure to explain the upsurge in per capita con- 
sumption of processed potatoes in terms of price and income changes indicates that 
changes in tastes and preferences must have occurred. 

Production. During the past half century, the potato industry has been 
characterized by sharply declining per capita consumption, rapidly increasing 
specialization and concentration of production, greatly improved breeding and 
cultural methods, and significant changes in utilization and marketing practices. 
These and other forces have operated to bring about a big increase in productivity. 
Between 1920-24 and 1960-61, yield per acre almost tripled, while acreage declined 
almost 60 percent. During the same period, total production increased less than a 
fourth. 

The big acreage and yield changes in the various areas have resulted in 
significant shifts in the seasonal and geographical patterns of potato production. 
Output in the States producing early potatoes (roughly winter and spring crops) about 
tripled between 1920-24 and 1960-61, but output in the intermediate States declined 
almost a third. Total production in the States producing late-crop potatoes, which 
makes up about four-fifths of the annual total, increased about 15 percent. 

The trend has been toward increasing specialization and concentration of 
production. Production of late-crop potatoes in the West over the 40-year period 
more than doubled (and its share of the total late crop increased from 20 to 45 percent). 
In the central region, production of late- crop potatoes declined sharply, with North 
Dakota the only State showing an increase. (In 1960-61 the central region produced 
only a fourth of the total late crop compared with almost half the crop in the early 
1920's. ) Late crop production in the eastern region showed only a modest increase, 
but production in Maine almost doubled. 

Number of farms producing potatoes has declined sharply while average size 
of farm increased. The trend toward specialization in production created problems 
for potato growers, particularly those in areas not well suited to mechanized, large- 
scale production techniques. 

The trend toward specialization in production, which in general has meant 
production concentrating in areas far removed from population centers, the increas- 
ing proportion of the crop sold, and more marketing services have resulted in big 
increases in both the importance and the cost of marketing. Because of the long 
hauls involved, freight rates from leading producing States to some of their principal 
markets average 40 to 80 percent of the farm price. Increased washing, grading, 
sizing, and packaging also have added to the role and costs of marketing. 



15 



Changes in merchandising practices have had an important impact on the 
potato industry. Pot^.to growers and shippers, to compete successfully, have had 
to adjust their marketing practices and services to meet the changes. 

Instability in potato prices and income to producers results from a combina- 
tion of the inelasticity of demand for potatoes and variations in production. During 
the decade studied a 1-percent change in production of potatoes resulted, on the 
average, in a 4 to 5 percent change in prices to growers. About 60 percent of the 
year-to-year variation in production was die to changes in acreage, and 40 percent 
was due to variation in yield. 

Look ahead. To look at what lies ahead for the processed potato industry as 
a whole, let's briefly review the development of the last decade. In the short space 
of 10 years, production of processed potato products, excluding chips, rose from 
about 200 million pounds of finished product utilizing less than 700 million pounds of 
potatoes to over 1 billion pounds of finished products using over 3 billion pounds of 
potatoes--about a four-fold increase. Chips, a big seller 10 years ago, are even 
more so now, outstripping increases normally expected though population gains by 3 
to 4 pounds a person. 

Of the newer products, frozen forms have shown the most spectacular growth. 
The instant products (flakes and granules) also grew rapidly until I960. Since then 
the picture has been somewhat confused. Several explanations have been offered for 
the fall-off in this^segment of the processed market. Some have speculated that 
instant potatoes have followed the cycle which characterizes the sales pattern of many 
new products. That is, after a period of introduction and a period of market growth, 
a market saturation position is reached. Others say the initial rapid growth led to 
ove renthus iastic expectations. New firms entering into business led to excess 
production capacity and the disruption of orderly market development. As a result, 
readjustments are being made in line with current market absorption capacity of 
quality products and a slower market growth potential than was formerly envisioned. 

The growth of the food market in terms of quantity directly depends upon 
population growth. Total intake per capita of all foods seems to be relatively 
stabilized at 1400 to 1500 pounds per year. Population gains are important, of 
course, in making food the biggest industry in the United States. But also of great 
importance in providing stimulus are changes in income, which reflect a variety of 
influences. Among them is the shift to foods in a more advanced state of preparation 
as consumer income increases. Even if consumption remains stable on a per capita 
basis, total potato consumption will be 25 percent greater by 19V5 than it is today, if 
projected population increases are realized. Any further gains on a per capita basis 
will of course swell your market further. In your attempt to achieve these further 
gains you will encounter intensive competition from other food products. 

The same 25 percent gain in volume holds true also for processed potatoes. 
In this segment of the industry, however, it is more a minimum rather than maximum 
prospect. Most observers agree that processing will register large gains. Some 
predictions have been made that would put one-half of the potato crop in the proc- 
essed category by 19V0. Since processing now takes about one-fourth of the crop, 
that, if true, would amount to a 100 percent increase by the end of the decade. 



16 



INDUSTRY OUTLOOK FOR FRESH POTATOES 
AND FOR PROCESSED POTATO PRODUCTS 



A. E. Mercker 
National Potato Council, Washington, D. C. 

The potato industry has changed drastically. It is now a dynamic growth 
industry, and of the 1488 pounds of food eaten by each person annually, 113 are 
potatoes. In other words, one out of every 13 mouthfuls of food eaten is potatoes. 
It is no wonder that so many processors and manufacturers of competitive foods 
look at potatoes with envious eyes and try to make inroads into the consumption 
of potatoes by substituting their products. This has been attempted time after 
time, and by what is considered unethical advertising means. Nothing is to be 
gained by tearing down the other fellow's product, but attempts are made toward 
this end. 

There is no better all-around food than potatoes. They have the nutrients 
necessary to supply the body, except fat, and this can be obtained from other 
products. Dr. J. B. Brown of Ohio State University, Chairman of the Department 
of Physiological Chemistry and Pharmacology, and a Director of the Institute of 
Nutrition and Food Technology, has stated that a person could live well by eating 
potatoes and drinking a quart of milk a day, although it would be a monotonous diet. 

Potato processing reversed the declining trend in per capita potato consump- 
tion and increased food use from 160 million cwt. in 1951 to 212 million cwt. from 
the 1963 crop. Of the 1963 crop, processing has used about 24 percent and 32 percent 
of that portion used for food. Of the 65 million cwt. used for processed food products, 
potato chippers used 46 percent, frozen prepared potato products used 34, dehydrators 
used 15, and 5 percent was used for flour, canning, and meat and vegetable and 
potato combinations. Lately, from a percentage standpoint, the frozen prepared 
potato products industry has shown the largest growth. 

Potato production. Potato production has been maintained in the East and 
the North Central States, with a tremendous expansion in the Western. In the West 
43 percent of the crop is now produced, compared to 28 percent in 1954. Early 
potato production, after great expansion, declined to some extent, but has leveled 
off lately. The expansion in the West can be partly attributed to the dependable 
supply of high-quality varieties which induced the establishment of processing plants. 
The Russet Burbank, the highest-quality major variety, is now leading. About one- 
third or over 100, 000, 000 cwt. of this variety is produced throughout the United 
States, Idaho has maintained its place by producing about 54 percent of the total. 
Production of late Red varieties has declined slightly, probably because consumers 
have shown some prejudice toward red potatoes due to the adding of red dye, which 
runs or bleeds and discolors many kitchen utensils as well as the hands and 
clothing, and have therefore been inclined to curtail the purchase of this variety. 

The decline in the number of potato farms is continuing and we have fewer 
but larger farms. In 1959, 20, 000 farms produced 94 percent of the crop on 20 
percent fewer acres. Idaho, Maine, North Dakota, New York and Minnesota had 
most of the farms growing 50 acres or more. The potato farmer has probably been 



17 



more efficient than others. He has trebled his yields in less than 30 years, and his 
production has retarded his own financial status to the benefit of distributive 
channels, retailers, processors, and many allied industries, such as the package 
manufacturer and the transportation and oil companies, and consumers. 

Processed potato products. The largest proportion of processed potatoes is 
used for the manufacture of potato chips. This industry has grown about 6 percent 
per year. In 1961 it grew about Z5 percent. The availability of low-priced potatoes 
and vegetable oils acted as an incentive. From the 1963 crop, however, production 
was no greater for chips than it was from the 196Z crop. No doubt the high price of 
potatoes from April on was a factor. 

Up to now the potato chip processor has taken raw potatoes that make light- 
colored chips and when there was a curtailment in the availability of such raw 
material, premiums were paid for those potatoes that would meet his specifications. 
During the 1963 marketing season, when the situation became tight for such potatoes, 
a premium of from 25 to 40 cents per cwt. was paid from January through March in 
the Eastern States above the price paid for potatoes for fresh use. This premium 
went up to as high as $1. 50 for late potatoes in April, and when the supply of late 
potatoes was exhausted the chipper was instrumental in establishing and maintaining 
the high price for early potatoes. The chipper needs a continuous supply, and up to 
the present he has been unable to store early potatoes to make a satisfactory end 
product. However, electronic rt«xhinery (micro-wave oven) has been developed 
which may change this situation and enable any desired color of chip to be made from 
almost any kind of potato. This may revolutionize the entire industry. A companion 
to the potato chip industry is the potato stick, or shoestring potato industry, which 
has had a slow growth and now is producing an estimated 50 to 60 million pounds of 
finished product annually. 

Frozen and dehydrated potato products. This industry has shown a consistent 
growth. There was only one setback, and that was in 1957. The industry had gone 
through a terrific expansion, more than doubling its production in 1955, and again 
increasing its production almost 30 percent in 1956. Production had exceeded the 
efficiency of its selling ability and therefore the inventory had to be reduced. 
However, substantial recoveries were made after that, with a growth of 2Z percent 
in 1958, 40 percent each in the years 1959 and I960, and a 5 percent increase in 
1961, followed by over 30 percent in 1962. The estimated growth for 1963 for the 
United States is between 13 and 15 percent. About 70 percent of the production, 
however, is sold to restaurants. About 86 percent is in the form of frozen French 
fries, the remainder being in many different forms. 

The dehydration industry (potato flour excepted) has used about 15 percent of 
the production used for food purposes. The growth has been gradual and sound, with 
the exception of a setback in 1961. Exports from the 1962 crop to Western Europe 
helped the situation for that crop year. Exports this season have been very limited. 
The industry now is on a sound basis. The quality is greatly improved although we 
cannot avoid abuses by persons preparing these processed potatoes for the table. 
There is much to be desired in educating the consumer to cook a better product. In 
my judgment, practically all of the cubes are used by other food processors. About 
50 percent of the flakes and granules are packaged for institutions. The rest are 
packaged in consumer-size packages. The industry is to be highly complimented on 



18 



the new products made available, particularly the frozen potato soups and dried soup 
mixtures. These are all excellent products and are filling a need. 

In summation: (1) The bloom is off as the novelty of new processed forms of 
potato products have filled the desire of the curious. (3) Processed potatoes are 
highly competitive with not only the different forms of processed potatoes but also 
prepeeled fresh potatoes and the many other convenience food items. (3) From now 
on further growth is largely dependent on merchandising and advertising, as 
advertising stimulates a creative demand for the products. Price currently is not 
the dominating factor as the advertised brands supported by high-quality products 
and service still stay in business in spite of discounts and discount houses. (4) The 
development of other forms and combinations is basic, such as casseroles, au gratin, 
meat balls and potatoes, and such other combinations that have been market- tested. 
People buy the end product and it must be a quality product. (5) This in turn re- 
quires a big volume as the investiment in research, market testing and consumer 
attitudes necessitates a large investment of funds, which, in turn, means that well- 
established food processors with established reputations as quality producers are 
needed in this field. Fortunately there are several such companies that interested 
themselves in potatoes. (6) Brand loyalty will create the demand and market, not 
price. (7) This means that the business will tend to move into fewer and stronger 
hands that can make the required capital investment, prepared to expect very little 
profit until there is a further demand for potato products, which, in turn, will 
stimulate production. (8) It is necessary to lick the flavor and texture problems. 
Considerable work should be done in this connection. ^9) The freeze dry method has 
possibilities, particularly as it preserves flavor, but again, the investment in this 
method is large. There is no threat from abroad as our product is superior to most 
of those made abroad. 

Fresh potatoes. Fresh potatoes after showing a sharp decline have leveled 
off at not less than 76 pounds per person, as the people who prefer fresh potatoes 
show a terrific resistance to other forms. The per capita fresh use has not gone 
below 76 pounds. This is indeed a tribute to the improvement in packaging and 
grading. It is still the big market and should receive much more support on the 
part of all distributors and shippers. The fresh market has not been supported by 
intensive advertising as it should be. The retail value of potatoes sold fresh is over 
$900 million, and less than $300, 000 is spent to advertise potatoes for fresh use. 
The potato chip industry for 1961 spent about $2, 600, 000 in advertising. The dried 
potato industry spent nearly $1Z million to advertise its product. General Mills spent 
about $7 million; Borden Foods and Pillsbury spent $1 million each; and the R. T. 
French Company about $3 million. Campbell Soup Company's advertising expendi- 
tures must be considerable. 

These heavy advertising expenditures are doing a splendid job in calling the 
public's attention to potatoes, not only in processed forms but in other forms. The 
frozen potato products industry has spent about a million and a half dollars advertis- 
ing their product, which has a retail value of about $140 million. The retail value of 
the dehydrated products is about $55 million. 

As long as personal incomes are maintained at high levels, people are willing 
to pay a premium for high-class convenience products, which include potatoes, and 
the 1964 early potato marketing season has shown that a high premium will be paid 



19 



for the fresh product provided it is good. This has been amply demonstrated by the 
marketing trend and price of fresh potatoes f. o. b, shipping points during May, June, 
and early July of this season when the per capita production was adjusted to slightly 
below our requirements. No doubt the processing industry has benefited from better 
prices in that the demand for their products has increased. 

The outlook for the continued use of fresh potatoes is good provided quality 
is maintained. Our per capita consumption of 113 pounds of all products is far below 
that of other countries with high standards of living, such as Belgium, where it is 
315 pounds; Denmark, Z80 pounds; Sweden, 200 pounds; West Germany, 372 poands. 
In 1961 per capita consumption in Canada was 150 pounds. Certainly the industry has 
the ability to increase per capita consumption. The healthful qualities of potatoes 
have not been advertised to any extent, and that is why we have the inroads of other 
foods. 

As to processed potatoes, the bloom of large profits is off. This business 
is now highly competitive and there have been some casualties. In the food business 
it is necessary for processors to make contracts with their customers for a period 
of 12 to 18 months in order to assure them a continuity of supply that will meet their 
exacting specifications. The industry is in a shaking-out period, and I am glad to 
see substantial companies engaged in the sale and distribution of these fine products. 

From now on it is an intensive, highly competitive business. However, the 
trend for the last 18 months has shown a steady increase in the use of most of the 
products. There is room for growth in the institutional field. There are over 
500, 000 public eating places in the United States. Certainly the processor can 
greatly expand the use of his products in this area. 

For the fresh market the potential is great. We have a civilian population 
of 187 million. The use of potatoes in homes can be greatly increased if we make a 
united effort to tell the public of the wholesomeness of potatoes. Even a 3 percent 
increase in this direction would mean an added need for 20 million cwt. of potatoes, 
or a total food need of about 230 million cwt. It can be done, provided all branches 
of the industry unite in a concerted effort to expand the use of its products. 



2 



WASHINGTON POTATOES FOR PROCESSING: CHIPS, STEWS, SALADS 



Paul Hackstadt 
Nalley's, Inc. , Tacoma, Washington 

No longer are potatoes just "potatoes". The sale and usage of processed 
potatoes continue to increase presently accounting for approximately 25 percent 
of the national production. Less than 50 percent of that amount is used by the 
chip industry. Competition is keen and the public is becoming more and more 
exacting in its demand. The rapid increase in tonnage used for processing has 
brought about some radical changes in production, resulting in accelerated programs 
to find better varieties, methods of growing, and facilities for production. The end 
usage now determines the varieties, cultural practices, and methods of handling and 
s to r ing . 

Potato processors are generally an aggressive, dynamic group, continually 
striving to improve their products by the use of the most modern equipment. Many 
growers have specialized and grow solely for processing. This is particularly true 
for chipping. However, even with the best equipment and the best information about 
growing and storing, the end product still depends on that lowly tuber, the spud. 

The potato chip industry needs a potato that gives good yields, fries into a 
finished chip of light color throughout, is uniform in size, has good texture, and 
tastes good. The tuber should have the ability to recondition out of storage and 
should be free of hollow heart, stem-end discoloration, or any internal defects 
which would affect the finished product. Full maturity is a prime requisite, 
particularly in potatoes that must be stored. This is a large order, but we hope 
that these requirements can be met by one of the new varieties being tried at present. 

Grade or external appearance is becoming more and more important. 
Increase in mechanized harvesting and handling has in many cases resulted in 
excessive bruising. This causes above-normal trim loss and less yield. A lot 
of potatoes badly bruised may be impossible to clean up properly because of the 
time and labor involved and therefore may be a loss to both grower and processor. 
This bruising can also cause severe losses in storage by opening the way for 
secondary infections. 

The Russet Burbank has for a long time been the most important variety 
grown in the State of Washington. When grown and stored under proper conditions, 
it chips satisfactorily. The specific gravity is usually high, thus giving good yields. 
However, this potato has some serious disadvantages as a chipper. The shape is 
oblong, which causes difficulty in mechanical peeling and increased labor in hand 
trimming. The slices are usually long and narrow, because the tuber rests on its 
side in the slicer and is cut the long way. This variety will not always recondition 
completely and the stem end will fry dark. The chip then will be snow white on one 
end and dark on the other, making removal on the pick-off belt virtually impossible. 

The Kennebec has gained rapidly in popularity and when grown properly 
fries into uniform light- colored chips. It tempers out of storage very nicely, is 
normally high in solid matter and yields well. This potato has a tendency to be 

2 1 



affected by hollow heart, will grow big unless planted with a short drop, and puts 
out long stolons which result in considerable greening unless hilled adequately. 
Kennebecs give good yields but size must be kept down by the careful use of 
fertilizer. Too much nitrogen and potash may cause oversized tubers and delayed 
maturity because of vigorous top growth. 

There are other varieties of minor importance in Washington. Some 
Norlands are used in mid-summer and are a high-yielding, early maturing type. 
They must be used promptly because of a tendency to revert and not recondition, 
Snowflakes, Merrimacs, and a few others have been tried, but have been disap- 
pointing because of tendency toward internal troubles or discolorations. 

Almost any variety grown in this state may be used in stew. A desirable 
potato for this use is thin skinned, shallow eyed, free of any internal or external 
defects, has the ability to retain its form after dicing and cooking, and does not 
turn gray. As a rule Western grown potatoes do not have a graying tendency. 
Caustic peelers are used because all skin and blemishes must be removed. A 
thin skinned tuber, free of bruises will yield better. Shallow eyes require less 
hand trimming, resulting in lower labor costs. 

Hollow heart and other internal defects are extremely important. If 
internal troubles are found, each tuber must be cut so as to find the defect before 
dicing. If discolored or defective dice are mixed into the batch tubs, the whole 
operation must be stopped while they are removed. Potatoes with black spot are 
nearly impossible to trim properly with normal labor costs. Sloughing of the dice 
can be troublesome in stew but as a rule the dice are put into the can raw and then 
retorted. There is no agitation and the dice retain their form very nicely. Russet, 
Burbanks and the White Rose are quite satisfactory. Generally they are free of 
internal troubles and are fine for stew. 

Potatoes for salads should have the same qualities as for stew, plus the 
ability to remain in diced form and not slough or break up in the finished product. 
White Rose is a good variety here, particularly at harvest time when peeling 
losses are low. It generally has low specific gravity and will not slough after 
being pre-blanched and then mixed with the other ingredients. Some other varieties 
may be used with good results, but usually the tubers with high specific gravity and 
of mealy consistency will fall apart after blanching. 

It is obvious that no one variety satisfies all requirements. Even the same 
variety gives different results when grown under varying conditions. Some potatoes 
chip at harvest time but may be impossible to use out of storage. Others give good 
results when grown in certain areas but will respond poorly in other areas. 

Although growers and chippers, aided by the hard work and help of Federal 
and State horticulturists, have accumulated good basic knowledge of the proper 
cultural and handling procedures necessary for good chipping potatoes, much more 
research must be done to gain a better understanding of the complex chemistry of 
potatoes. Answers to the following questions must be found and controls established 
before we can hope to consistently produce a chip of uniform color, texture, and 
flavor. 

2 2 



Exactly just what chemical action takes place within a potato that causes the 
finished chip to be dark in color and bitter in flavor? What causes this to happen to 
a good lot of potatoes within a matter of hours or days? Sugars and amino acids? 
Immaturity? Temperature? Most likely some of each, but to what extent or degree? 
What other factors or combination of chemicals might cause this to take place? How 
can they be controlled? The need for more research in all phases of the potato 
processing industry is certain and undoubtedly the search for information will be 
perpetual, but perhaps in the near future, production of uniform good potato products 
will be possible under any condition of growing, storing, handling, and processing. 



QUALITY REQUIREMENTS OF POTATOES 
FOR PROCESSING: FROZEN PRODUCTS 

C. R. Miller 
Stokely-Van Camp, Inc., Zillah, Washington 

About 11 years ago our company ventured into the frozen French fried potato 
processing business. This surely must have been part of the golden age for the 
French fry. Few processors were in the business. The demand was good and 
growing fast. Virgin soils were coming under cultivation in vast areas of the North- 
west, Potatoes were being planted in overabundance and they were of good quality. 
Nearly all the French fries produced were sold as fancy grade at a profit. The 
buyer and consumer were not too hard to please. 

Processors met the problems and challenges as separate and individual 
operators. They used whatever knowledge was available and improvised the rest. 
Thus they advanced toward a common goal of improved methods and quality by their 
own imaginations and trial and error. And then began a period of potato plant 
expansion which during the past six years has equaled anytJiing ever seen in the food 
industry. Plants were built everywhere, and existing facilities expanded. This was 
the result of a new promising industry and the availability of nearly unlimited 
investment funds. 

The brief period of expansion brought with it a complete change in the 
economics of the industry. The under supplied market became oversupplied or 
nearly so. The finished .product became pressed to find profit in the market place. 
Buyers and consumers are now more knowledgeable in their acquisition and use of 
potato products and they require higher standards. The processor has become 
acutely aware of this need to fulfill quality requirements and to meet standards from 
the competitive standpoint. 

No longer does the processor finish the day with 95 to 100 percent fancy 
product, in one or two styles of cut, and in a very few sizes of packages or labels. 
Today most processing is done by seasoned personnel well skilled in production 
techniques. The processors are monitored by a highly trained staff of quality con- 
trol people or by continuous USDA inspection or both. The product is now produced 
to the exact specification of the company or the buyer. Many styles and grades are 



23 



produced and packaged into multitudes of labels and brands. These are shipped in 
containers of various shapes, sizes, weights and types. In other words we have 
been growing up and are taking our place in the highly specialized and competitive 
food industry. 

We have mentioned that in earlier years quality of raw and finished products 
was not too much of a problem. Today quality is a prime factor and requires 
diligence and perseverance on the part of everyone, especially the grower s, handlers, 
and processors every hour of the day and night. A prerequisite to good quality of 
finished product is now, and always has been, good-quality raw material. To 
discuss raw product quality we must specify what finished product qualities are 
essential and how they relate to raw product. 

The more important finished-product qualities are texture, absence of 
defects, flavor, color, and size or length of individual units. Most of the material 
here relates to the frozen French fried potato products such as fries, puffs, cottage 
fries, but in general they also apply to other frozen potato products except those 
which are made for specialized uses such as soups and stews. 

The first item -- good texture -- is found in a product whose external 
surfaces are crisp, show no noticeable separation from the inner portion, and are 
not excessively oily. The interior portions are well cooked, dry and mealy, tender, 
and practically free from sogginess. Further, the individual units and total product 
should be uniform in these attributes. 

What characteristics in the raw product contribute to texture? Number one 
would be a uniformly good specific gravity or solids content. This would be in the 
range of 20 percent up to Z4 percent or higher. Low-solids potatoes tend to produce 
product which is wet in character and absorbs more cooking oil. 

When we speak of the percent solids of a field or lot of potatoes, the reference, 
of course, is to the average of all the potatoes in that particular group. In practice, 
the potatoes in a particular field or unit might vary from 16 to 17 up to 23 or 24 per- 
cent and the average solids might be 20 percent. So we have a difference between 
individual potatoes. Also there is a difference between stem and blossom ends and 
again a difference between the external and internal parts. Thus we see that each field 
or lot of potatoes varies considerably and we can assume tliat different fields or lots 
will vary in range of solids. Therefore, a lot that averages 22 percent solids might 
produce a less desirable product than another field which averages only 20. The range 
is more important than is percent of solids. Some factors which contribute to varia- 
tion in solids are temperature, disease, growing practices (i.e. time of planting, 
fertilizers, rotation, irrigation), and varieties. 

Given the same variety and no abnormal conditions of disease or frost I 
believe that in the irrigated areas of the Northwest temperature during the tuber- 
formation period is the most important single factor affecting solids. Prolonged 
periods of excessively high temperatures not only tax the ability of the plant to 
develop normal tuber size and solids content but also the diseased, injured, or 
deficient individual plant may produce tubers which greatly exaggerate the variation 
in solids and cause severe complications to the processor. 

24 



Net necrosis causes wet, stringy, oil- saturated units and a dark muddy ap- 
pearance of the affected part. The other diseases affect the quality of the potato, 
both fresh or processed, by causing early dying, discoloration, unevenness of solids 
within the tuber and uneven distribution of certain other elements. These factors in 
turn cause poor texture or color in the finished product. Sunburn affects the texture 
of the finished product by causing the potato to remain tough or hard after blanching 
and frying. 

Color is essentially the result of the accumulation of sugar in the raw product. 
Most potatoes processed from the field during the summer present no problems 
colorwise and they generally fry to a light even desirable color. Color problems 
ordinarily develop during and after harvest for storage. Potatoes which are planted 
early and have become overmature in the ground do not accumulate sugars as much 
as less mature potatoes. 

Inadequate or poorly regulated storages are two of the more important 
causes of bad color conditions. However, potatoes chilled in the field or during 
harvest are also a serious source of color problems. Other color problems involve 
the uneven distribution of color-forming chemical properties within the tuber, 
causing one end to fry darker than the other. One thing is certain: a field or lot 
of potatoes which are a little too light or a little too dark are much better than 
potatoes which are mixed light and dark. 

Defects can be divided into three groups: trimmable defects, sortable 
defects, and those which cannot ordinarily be trimmed or sorted. The trimmable 
defects include those which appear on the surface such as scab, rot, bruises, sun- 
burn, growth cracks, insect damage, cuts, net necrosis, stem-end browning, etc. 
While these are listed as trimmable defects, the degree of severity determines 
whether the product is trimmed or discarded. 

Sortable defects are those which are not visible after the potato is peeled but 
can be detected after the potato is cut or sliced. These include hollow-heart and 
internal discoloration. The last group (neither trimmable or sortable) includes heat 
necrosis, frost necrosis, net necrosis, insect damage such as flea beetle or 
nematode, and bacterial breakdown. These defects when at all severe cannot be 
economically removed. 

Removing defects constitutes the largest single labor expense in processing. 
The amount and kind determine whether the potatoes can be processed and whether 
they will be processed at a profit or a loss. They may also determine whether the 
finished product will be fancy. Defects determine the percent recovery of fancy 
product and also the percent recovery of finished compared to raw. 

The size of tubers influences the percentage of types and grades of products 
that can be produced. Ordinarily the larger size is desirable. Excessively small 
potatoes yield high percentages of less desirable outside cuts, too many short units, 
and the ratio of surface area (where most of the defects are) to weight of usable 
product is too high. Also, the loss from skin removal is higher with small potatoes. 



25 



Flavor is a less tangible factor in the raw product unless influenced by such 
things as sunburn or scald, tissue breakdown, bacterial decomposition, exposure to 
cold, or chemical contamination. 

Now that we have briefly discussed some of the quality factors you might say 
that every field or lot has some deficiencies such as bruises, cuts, black spot, 
hollow-heart, disease, sunburn, etc. If there are more defects, can't processors 
just add more workers to trim and sort them out? How good a raw product do you 
need? What tolerances for defects? Or better, what kind of defects can you tolerate 
in your finished product? How important are the factors affecting quality? 

It seems to me that the answers to some of these questions are essential to 
the grower, handler, scientist, and processor before each of us can fulfill his 
proper function. The feeling in the past and to some extent still prevalent, that the 
processors' raw product requirements fall between the fresh market and the starch 
plant or cattle feeder, is erroneous. Of course you can have a situation where a 
certain lot is otherwise good but cannot be economically sold fresh because of 
appearance or shape. Then these potatoes may be better used for processing. 
However, except for shape and appearance, the requirements for processing potatoes 
are much more specialized and restrictive than are those for fresh market. The 
potato must be relatively free from defects, must produce the proper texture, fry to 
the proper color, and be reasonable in size for the product intended. 

What does "relatively or reasonably free from defects" mean? This of 
course depends upon the individual processor's standards, but I would venture a 
guess that if the trimmable or sortable defects exceed those allowable for USDA 
No. 1 potatoes the processor will suffer in cost, in grade, or in the production of 
his finished product. 

What about the limits or tolerances for units of poor texture? Would 3 to 6 
units per 100 units seem restrictive? 

The average number of pounds trimmed per person can and does vary from 
IZOO to over 6000. The percent recovery can vary up or down 10 to 15 percent. The 
percent fancy can vary from to 85 percent. All production from a certain lot may 
be relegated to the status of distress merchandise of questionable value. When we 
consider these things, then it becomes apparent that poor quality at any price is 
poor economy. 

Just a word regarding varieties. The most used potato in this area is the 
Russet Burbank followed by the Kennebec, the White Rose, and the Early Gem. 
Other varieties have been or are being tried with varying degrees of success. 
Kennebec has many good points such as consistently high yield, tolerance for dif- 
ferent moisture conditions, good size, resistance to certain diseases. On the 
debit side, it is a poor storage potato, tends to shatter when cut, and is less 
reliable texturewise. White Rose processes quite well if solids are high. It 
resists bruising. However, when overmature the eyes won't peel, and it has a 
tendency toward off color and oxidation. 

Because of its consistent ability to produce finished product of high quality, 
the Russet is by far the most used potato. Despite this, the Russet has many 



26 



draw-backs. Among these are low resistance to bruise and black spot, susceptibility 
to a variety of diseases such as the wilts and net necrosis. It also has a high 
incidence of rhizoctonia and a tendency toward hollow-heart, growth cracks and mis- 
shapen tubers. In my opinion the Russet while still the most popular processing 
potato, has too high a risk factor to the grower and the processor. Except for those 
who still sort out the better potatoes for fresh market and process the balance, the 
grower and processor would be better off with a potato which is not beset with all of 
the pitfalls of the Russet. 

I believe, for the present, we should exert greater effort to learn how to 
overcome the inherent problems with our present varieties. Looking to the future, 
our efforts should be redoubled now to develop new varieties which will better meet 
requirements. Today we are competing with the people next door or in the next 
county or state, but tomorrow, who knows, perhaps the whole world. 



GROWER-PROCESSOR RELATIONSHIPS 

Donald B. Robertson 
J. R. Simplot Company, Hayburn, Idaho 

In a discussion of current grower-processor relations, I think it is neces- 
sary to take a look at the past. As the industry has become more refined and 
sophisticated, so has the culture and marketing of the grower's crops. Today's 
grower is better informed than ever before. How did this come about? 

Twenty years ago, we were primarily a fresh potato packing company and 
secondarily interested in the possibilities of processing. We of the J. R. Simplot 
Co. like to feel we were the pioneers in this now tremendous industry. The 
operators of our fresh packing sheds were the procurement agents for the then 
struggling processing segment. The fresh-pack operator recognized the size, shape, 
and defects of potatoes and priced the farmer's crop according to the daily market. 
He wanted to be a good fellow and he quite often would buy a grower's crop for the 
processing plant even though he would not have bought it to run through his shed. 
As a result, processors became the disposal, gaining the reputation of using inferior 
potatoes and making products to compete with fresh potatoes and getting fabulously 
rich. True, processors could use shapes and sizes not of fresh-pack quality to 
produce dehydrated products, Raw potato requirements changed rapidly with the 
advent of new frozen products. However, the idea persisted and still does, though 
much has been done to overcome that old concept of buying potatoes for processing. 
Today our fieldmen are primarily concerned with processing and the procurement 
for processing. Many are ex-fresh packers and they have had to change their ideas, 
some being as difficult to change as the growers we deal with. 

The old fresh packer offered the grower a minimum of assistance. Some 
recommended seed or fertilizer, but largely they left culture to the grower. When 
the crop was harvested in the fall, they were the horse traders, haggling price with 
the grower and each trying to make the shrewdest deal for himself. 

27 



In 1954 Idaho produced 24, 480, 000 cwt. of potatoes. Of this portion, 
perhaps 15 to 20 percent went to processing. Most of these were open-market- 
purchased and of the lower quality or the marginal part of the crop. In 1963 
Idaho produced over 52, 000, 000 cwt., more than doubling production in ten years. 
Processing used over 40 percent and roughly 30 percent were contracted by 
processors. For those who would say it is true the fresh market has suffered, 
I would point out that in the past year Idaho shipped in excess of 30, 000 of the new, 
heavy cars of fresh potatoes to market. It is interesting to note also that 8 of the 
Idaho processors are very active in the fresh movement. Processors are now 
more selective in open-market buying than ever before. 

Today our grower relations continue 12 months out of the year. To keep 
the grower informed, we must have informed contact or field men. How do we 
accomplish this? What is the program? First, we must educate our own 
personnel and they in turn disseminate their knowledge to the grower. The best 
source of information is the USDA and its agencies. We in Idaho have the 
University and the Extension Service with the research station at Aberdeen. The 
county agents, potato specialists, and research personnel at the experiment 
stations are our friends and advisers. We have differences of opinions and are 
at times critical of each other, but we cooperate to the fullest to keep the grower 
informed. 

Through our processors' association, the Northwest Canners and Freezers 
and other industry- sponsored groups, we learn and spread up-to-date information. 
We conduct our own research farm and laboratory. We test fertilizers, weed 
control, seed varieties and many pertinent cultural practices. We conduct or 
cooperate in conducting tours, workshops, and classes. These workshops are 
for the growers, some for field men and some for both. We feel our field men 
are well enough equipped to be good advisers to our growers. If we get stumped 
by a problem, we long ago learned to call the University research people for help. 
They in turn quite often ask us for help, which we freely give. Through our 
program, we urge the growers to become acquainted with and visit the Aberdeen 
Station and attend Extension meetings. Many of our growers are extremely well 
versed in up-to-date ideas and work with the research people. 

In today's grower-relation program, we have to be aware of the problems of 
the grower and help him overcome them. By the same token, he must know and 
appreciate the many new aspects of potato quality that processing has created. 
Many growers have problems they don't recognize and they welcome help. They 
must be made to realize that price is not the complete answer to financial stress, 
but increased production of higher-quality potatoes will pay high dividends. We 
have caused many growers to change their thinking through our contracts. Briefly, 
we emphasize size, shape, specific gravity, reduction of sugar controlled through 
proper storage, and proper handling to prevent bruising. We pay a premium on 
several of these factors. Through the work of the Aberdeen Station, we have 
induced growers to use better harvesting, handling and storage techniques. 

The grower is now aware that it is important that he control his fertilizer 
program and irrigation practices to induce high specific gravity. He must store 
his crop at a higher temperature to keep the reducing sugars down. We stress the 
problems he creates by mishandling and bruising his crop. By being vigilant and 



28 



informed, we have made the grower realize his responsibility in the use of 
pesticide chemicals. Last year we were instrumental in a cooperative school 
for growers on the use of chemicals. Today our program can be outlined as: 

1. Start out right by using only certified seed. 

2. Plan and prepare in advance the soil for the next crop. 

3. Use commercial fertilizer wisely after consulting the 
county agents, company field men, and after adequate 
soil sampling has been done. 

4. Cultivate and irrigate, using the latest findings and 
recommendations of research. 

5. Harvest with tender care. 

6. Store according to the findings of our processor associa- 
tion's and Aberdeen Station's joint studies. 

Our field men must be equipped to discuss each of the subjects in up-to- 
date language. In addition, they must know the price structure, the weather out- 
look, what insects or diseases are expected and what to do about them. They must 
be able to recognize proper soil moisture and danger signs the crop may show. If 
our field personnel don't know the answers, they will say so, but will also help find 
the answers. 

Each of our field men has a certain area and is assigned those growers 
within that area. All have been dealing many years with the same growers. They 
compete unconsciously with each other. "My area had the best yield and quality 
and my grower, John Doe, was the best grower of all. " This friendly competition 
does not affect their ability to help each otb.er on problems. They discuss their 
field department manager and the area manager as well as research personnel; 
together the problems are solved. 

In closing, I would say our close communication between our own personnel 
and close personal contact with our growers has helped us a great deal. Most 
important of all in successful processor-grower relations are: (1) Honesty in 
grower dealings. (2) Well informed field men, (3) A sincere desire to help the 
grower. K you will practice these three things, your grower relations will be 
a success. 



29 



POTATO UTILIZATION IN CANADA 



F. H. Hatfield 
Hatfield Industries Ltd., Hartland, New Brunswich 

Living in the space age means many things to you and me; faster planes, 
trains, and automobiles; ships ready to take man to the moon, to Mars and other 
planets; bigger computers, bigger rockets and bombs. Men and women must be 
healthy to stand the pace, Basic staple foods must be provided in time-saving, 
convenient forms. Potato processing is the answer of the potato industry to this 
need. 

Although potatoes were probably first cultivated in the western hemisphere 
about 200 A, D. , they did not arrive in Canada until 1624. History tells us that the 
captain of a British trading ship presented a barrel of potatoes to the Acadian 
Settlement at Port Royal, in what is now the Province of Nova Scotia, at about that 
time. 

From this start the potato industry in Canada has had tremendous growth. 
According to latest figures from the Dominion Bureau of Statistics at Ottawa, the 
total farm value of the Canadian Potato Crop is 70 million dollars. Potatoes are 
the largest farm cash crop in New Brunswick and Prince Edward Island. Seed and 
table potatoes from New Brunswick are sold in all Provinces and in a large area 
of the United States, This Province also exports to 21 countries. 

Potato processing in Canada had its start during World War I, when it 
became necessary to find methods of delivering potatoes to Europe to feed our army. 
Space was a problem. The water had to be removed and dehydrated potatoes were 
developed. Our textile, paper and munitions industries used starch for certain 
phases of their operations. Shipping space for imported starch was at a minimum 
and so the potato starch industry started to develop. These processed potato 
products were mainly wartime industries. The dehydrated product did not meet 
the approval of the civilian population. The potato starch industry did continue to 
grow slowly and the depression of the 1930*s added impetus to this growth when it 
was found that starch factories made convenient outlets for surplus. 

In 1939, at the outbreak of World War II, space again became a problem. 
Potato dehydration plants were built in the large potato growing areas: two in 
New Brunswick, one in Prince Edward Island, and one in Ontario. However, 
shortly after the end of World War II, these plants ceased operations. It was 
evident that their product was not acceptable to the Canadian consumer. 

In the early 1950's many factors gave impetus to the growth of potato 
processing in Canada. Our industries were growing. People's incomes were 
rising. Hours of work became shorter. This combination of more money and 
more leisure, combined with television, created a demand for new products. 
Two new terms came to the fore in our food markets, namely snack foods and 
convenience foods. Potato chips and French fries were the answer of the potato 
industry to the growing demand for snack foods. Dehydrated potato flakes, 
potato granules, and frozen French fries in all their different forms were the 

3 



answer of the potato industry to the demand of convenience foods. 

According to the latest figures issued by the Dominion Bureau of 
Statistics at Ottawa, 10 percent of the total Canadian potato production for the 
1962-63 crop went to Canadian processors. For the year ending June 30, 1963, 
Canada produced: 

50, 074, 765 pounds of potato chips and related products, 

32, 797, 942 pounds of frozen French fried potatoes and related products, 

15, 630, 459 pounds of pre-peeled and pre-cut potatoes, 

10, 769, 437 pounds of potato starch, 
5, 355, 362 pounds of dehydrated potato flakes, granules and potato crystals. 
It is also estimated that several thousand pounds of potatoes were canned and 
processed in sulphur dioxide. 

At present there are 29 potato chip plants operating in Canada. Two of 
these are located in Nova Scotia, 3 in New Brunswick, 11 in Quebec, 7 in Ontario, 
3 in Manitoba, 1 in Alberta, and 2 in British Columbia. Commercial production 
of chips started in the 1930's in Ontario. Production doubled between the years 
1958 and 1963. Per capita consumption for the year 1964 will be well over 3 pounds. 
Probably the greatest problem facing chip processors is the high cost of bringing 
in U.S. potatoes during the summer months. This period coincides with their 
period of peak demand and peak production. All potatoes from the United States 
enter Canada under a tariff of 37 1/2 cents per hundredweight. The Canadian 
Potato Chip Association has recently submitted a brief to the Government of Canada, 
requesting that U.S. potatoes entering Canada during the summer months for use 
in chip plants be exempted from this tariff. 

The potato research people of the Canadian Department of Agriculture 
are working closely with chippers in Canada in trying to breed a variety that will 
fry with an acceptable colour from storages kept at 40° to 45 ° F. Dehydrated 
potatoes in flake and granular forms are quite recent developments in Canada, 
The first flake plant was built by Salada Foods Ltd., in Alliston, Ontario, in 1959. 
This company holds full Canadian patent rights on the potato flake process. These 
patent rights have recently been challenged on several occasions and the matter is 
now before the Exchequer Court of Canada. 

Potato crystals, a dehydrated product developed by Dr. E. A. Asselbergs 
and the research staff of the Food Research Institute, Canada Department of 
Agriculture, are presently being produced by McCain Foods Ltd., in New 
Brunswick and by Carnation Foods Ltd. , in Manitoba. The McCain plant is 
exporting a large portion of its production to Europe. The potato crystals are 
manufactured under license issued by the Canadian Government and several other 
companies hold licenses to produce this product in Canada. 

According to the description in the application for patent on this product, 
"The object of this invention is to provide a new type of instant mashed potato, 
having a physical structure differing from the granular and flake. The invention 
provides a process for the production of a dehydrated, cooked, mashed potato 
product, comprising forming a perforated layer of mashed potato and drying said 
layer on a heated surface to form crystal-like particles having an average thickness 
of from about three to about four potato cell thicknesses. Emphasis has been laid 

3 1 



in the prior art on the use of a prolonged cooking period at relatively low tempera- 
tures. By contrast, for obtaining the product of the present invention, a relatively 
short cooking period is preferably used. Advantageously this is not more than 
15 minutes and is preferably about 7 to 10 minutes. " 

The production of frozen French fries in Canada ranks second to potato 
chips in volume. This product is produced in 7 of the 10 Provinces. There are 
3 plants in Prince Edward Island, 1 plant in New Brunswick, 1 in Quebec, 2 in 
Ontario, 1 in Manitoba, 2 in Alberta and 1 in British Columbia. A substantial 
tonnage from the plants in Prince Edward Island and New Brunswick is exported 
to the British market. The frozen French fry industry is rapidly growing in 
Canada and several plants have started production within the past two years. 

The McCain plant at East Florenceville, New Brunswick, is estimated to 
have the largest single share of the Canadian market. It certainly has the widest 
product range, with production of frozen French fries in 4 diameter cuts and 
3 lengths, along with potato gems, potato puffs, diced potatoes, baby boiled 
potatoes, baby roasted potatoes, potato patties, western home fries, potato 
crystals, potato chips, and potato sticks. 

Production of potato starch has had its ups and downs, based on the supply 
of cull potatoes. Production is concentrated in New Brunswick, with plants 
located at Hartland and Grand Falls. A new plant recently opened in Vauxhall, 
Alberta, 

In the report of the Royal Commission on the New Brunswick potato industry, 
it is stated that the average total annual consumption of all starches in Canada is 
122 thousand tons. This report also shows that the production of potato starch in 
Canada during the period 1955 to I960 was 20, 497 tons, with the crop years 1956-57 
and 1957-58 accounting for 13, 544 tons of this total. 

This Royal Commission stated that there is a ready market in Canada for 
10, 000 tons annually of potato starch and recommended that an industrial variety be 
developed to supply raw material for Canadian starch plants. Consequently a 
breeding program was set up at the Dominion Potato Research Station at 
Fredericton, New Brunswick, in I960. The Potato Breeding Section of the Dominion 
Research Station, under the direction of Dr. Donald Young and the Director of the 
Potato Branch of the New Brunswick Department of Agriculture, Scott Clarkson, 
co-operating with the 3 starch plants in New Brunswick, are working on this project. 
Very good progress has been made. 

At the 12th National Potato Utilization Conference, held at Bakersfield, 
California, Dr. E. A. Asselbergs of the Food Research Institute of the Department 
of Agriculture of Canada outlined the work of that Institute on the production of pre- 
cooked, instant foods made with fish, meat and cheese, mixed with mashed potatoes 
and pre-gelatinized starch. Canadian processors are watching with interest the 
development of this work started by Dr. Asselbergs and now carried on by Dr. 
N. W. Tape. In a recent letter from Dr. R. P. A. Simms, Director of the Food 
Research Institute, he advises that the following developments have taken place 
since 1962, under Dr. Tape: 



1. The true nature of quality in instant potatoes has been identified. 

2. The shelf life of potato protein mixes has been determined at 
various temperatures and under a variety of packaging conditions. 

3. Recipes and uses for these foods have been developed. 

4. Consumer acceptance tests have been used to show that the 
"Potato-Fish" product is liked in the Ottawa area market and 
a similar test on "Potato- Beef " is now under way. 

5. Canadian potatoes have been shown to be a completely acceptable 
substitute for the West African yam when used as the starch 
component of instant foods for the West African market. 

In cooperation with a Ghanaian student, Dr. Tape has developed two instant 
"Etohs, " one based on fish and the other on coarsely ground peanuts. 

Processors are watching with interest the development of the Canadian 
potato irradiation program by the Commercial Products Division of Atomic Energy 
of Canada Ltd. , under the direction of K, F. McQueen and J. A. Robb. Copies of 
their report on work conducted during the 1961-62 season using a mobile cobalt 60 
irradiator can be obtained by writing the Atomic Energy of Canada Ltd. , Com- 
mercial Products Division, Ottawa, Ontario. This mobile irradiator moved across 
Canada by rail and truck and treated many lots and varieties of potatoes from the 
1961-62 crop. Results show promise for a new method of potato sprout inhibition. 

What does the future hold for potato utilization in Canada? Personally, I 
feel that the future is bright. During the past two years processing seems to have 
reached a plateau. The pessimists say we have come too far, too fast. It is my 
feeling that we expected too much, too soon. We have pat comparatively high 
priced products on the market in competition with fresh potatoes, in a period when 
these same fresh potatoes were selling at depressed prices, due to overproduction. 
This spring and summer the potato growers are receiving good prices for their 
fresh potatoes. In the opinion of many in the fresh potato business these good 
prices will carry over into the fall and I fe'el that if this situation develops and a 
consistently high-quality processed potato is available on the market, it will mean 
a boom for the processed potato industry in Canada. 



THE RED RIVER VALLEY POTATO PROCESSING LABORATORY 



Roy L. Shaw, Jr. 
East Grand Forks, Minnesota 

The Red River Valley Potato Processing Laboratory is the result of needs. 
Industry members felt that knowledge at hand is not sufficient to assure consistent 
good quality for processing. All segments of the Red River Valley potato industry, 
and I include research, wanted to know more about what goes on inside the potato 
and how such goings on are influenced by varieties, cultural practices, agricultural 
chemicals and storage conditions. Moreover, what are the effects of these variables 
on processed products? 

The Laboratory is a cooperative venture of the Red River Valley Potato 
Growers Association, the North Dakota Agricultural Experiment Station, the 
Minnesota Agricultural Experiment Station, and the Agricultural Research Service 
of the U. S. Department of Agriculture. All four groups have funds invested, all 
have personnel at the Laboratory, and all participate in setting overall objectives 
and programs. The Agricultural Research Service as represented by Eastern 
Utilization Research and Development Division has the responsibility of directing 
and administering the programs and accomplishing the objectives. 

Assignments are (1) to study in detail the interrelationship of the sugars and 
to study the enzymes involved in this interrelationship, (2) to determine how varia- 
tions in varieties, cultural practices, agricultural chemicals and storage conditions 
affect this interrelationship, (3) to determine how this interrelationship can be 
controlled, 

I should emphasize at this time that the Laboratory was not planned to 
develop new processed potato products, although they may be by-products of our 
work. The Laboratory was not planned to do research on processing. Such 
research will continue to be done at the Eastern and Western Divisions where staff 
and facilities are available in Philadelphia and Albany, California, respectively 
and in the pilot plants of industry. The Laboratory was not planned to do service 
work. Such work is best done by those organized and equipped to do it. 

Because the ultimate test of any food is the fork test, the experimental lots 
of potatoes must be converted to finished products for panel evaluation. For this 
reason we have a pilot plant. The equipment was built by manufacturers of com- 
mercial scale units. In the pilot plant we can process 100 pounds per hour of 
potatoes under conditions closely comparable to those used by industry. 

The first year's work will be mostly exploratory. We have planted two 
varieties: Kennebec, which handles the sugars well during storage and recondition- 
ing, and Norland, which accumulates large amounts of sugars and reconditions with 
difficulty. These varieties will be harvested at two dates, approximately six weeks 
apart. They will be stored at 40° F. for 12 time periods and will be reconditioned 
at 65° at 4 intervals. Samples will be subject to pilot plant procedures and to 
laboratory analyses so far as staffing permits. 

3 4 



Pilot plant procedures will consist of processing a sample into chips or 
French fries or flakes or dehydrated pieces. We will make an evaluation in terms 
of color, flavor and simple chemical analyses such as sulfites and total reducing 
substances. Laboratory procedures will consist of fractionating sugars into various 
components and determining their amounts. We will also assay for the activities of 
invertase, phosphatase, phosphorylase, and transglucos idase . Depending upon 
where our exploratory results ieaa us, we may eliminate some of the above analyses 
or may add others. 

The Potato Processing Laboratory, although new, and focusing on the new 
areas of potato research, is only one part of a very large potato research program 
being carried on in the Red River Valley. The four cooperators including the 
Potato Research Farm in Grand Forks, North Dakota, and the Potato Research 
Center in East Grand Forks, Minnesota, have worked together for years in other 
projects and facilities. 



THE ABERDEEN POTATO RESEARCH CENTER 

George W. Woodbury 
University of Idaho, Moscow, Idaho 

Aberdeen, Idaho, is about Z5 miles straight west of Pocatello. Since much 
of the area between the two points involves portions of American Falls Lake, surface 
travel of some 40-50 miles is needed to reach one place from the other. 

State Highway 39 from Blackfoot, in a southeasterly direction, also leads to 
Aberdeen over a distance of some 35 miles. Bingham County, of which Blackfoot is 
the county seat, is one of Idaho'^s great potato producing counties. The general area 
is served by the Union Pacific Railroad and by U. S. Highway 91. Aberdeen itself 
has some 1500 inhabitants. The Aberdeen Branch of Idaho's Experiment Station was 
established in 1911, and potatoes have been under study there from the start. At 
present the Branch Station has a technical staff of 16 full-time employees, 10 of 
whom are in University service, the remainder with cooperating agencies. The 
Station at Aberdeen comprises slightly more than 200 acres of tillable land under 
irrigation, in addition to about 11 acres devoted to roads and buildings. Greenhouse 
and laboratory facilities are limited. The research at Aberdeen has to do 
principally with farm- crops -- cereals, sugar beets, alfalfa, and potatoes. Nine 
staff members work on at least one or more phases of potato production, which 
include insects, diseases, nematodes, breeding, nutrition, storage, irrigation, 
and harvesting. 

Idaho's place in potato production and marketing has been achieved by 
providing the housewife and others with a quality product. The Russet Burbank 
variety has been and still is the only important variety. Research on phases of 
production and handling has been going on for a long time, usually with a limited 
staff and always with inadequate facilities. Two important factors of recent origin 
have intensified the need for expanded research. These are (1) a highly significant 

3 5 



development of the processing industry, which now utilizes somewhat more than 
half of Idaho's potato crop, and (2) competitive production of Russet Burbank po- 
tatoes in other parts of the country. 

With the expansion of processing more and more attention is being focused 
on the constituents of the potato. What elements contribute to texture, color, 
taste, and general acceptance of the finished product, all of which constitute 
quality? The same thing is true, perhaps to a lesser extent, with the fresh product. 
Quality potatoes must be produced, however, and just as important, they must 
reach the consumer without being the worse for wear. 

The 37th meeting in 1963 of Idaho's legislature approved a total of $350, 000 
for a research facility to be constructed at the Aberdeen Branch Experiment 
Station, Sources of the necessary funds are: permanent building fund, $200, 000; 
Idaho Potato and Onion Commission, $100, 000; and $50, 000 from the potato 
industry, including growers, processors, shippers, and other organizations. 
Plans were subsequently drawn up for the building and bids were called for. 
Construction is now imminent. 

The building will cover approximately 12, 000 square feet. It is essentially 
a laboratory structure of two stories, with one story below ground level. On the 
main floor laboratories will be provided for plant physiology, plant pathology 
including nematodology, entomology, food technology, biochemistry, food engineer- 
ing, and plant nutrition. One large laboratory will be used for gross assays of 
quality. While provision may be made for pilot work on batches, such investiga- 
tions will be limited to quality factors. It is not anticipated that new products will 
be an objective. 

Growth chambers and refrigerated rooms will be located in the basement, 
each equipped with controls for maintaining desired conditions. The basement 
will also house soil and preparation rooms, as well as mechanical equipment, in 
addition to storage room for supplies and surplus material. 

While staff members now at Aberdeen are rather adequately located in 
office buildings, provision will be made for additional offices for those engaged 
in use of the laboratories. Service rooms for weighing, for glass and chemical 
storage, and glassware washing will be included, as well as a receiving area. 

The facility will be under the direct control of the Idaho Agricultural 
Experiment Station and will become an integral part of the Aberdeen Branch 
Station. All programs are coordinated with subject-matter departments responsi- 
ble for the research. Currently considerable potato research is in progress on 
campus and, to a lesser degree, at branch stations in South Idaho. Funds for the 
operation and maintenance of the new laboratory will be provided through regular 
University appropriations. 

The expanded program will be conducted, as in the past, with cooperation 
from Idaho's potato industry and the U. S. Department of Agriculture. Our 
research heretofore has been in plant breeding, harvesting and storage, nutrition, 
insects and disease, as well as marketing and distribution. Home Economics 
Research has also contributed to knowledge of texture quality and post-harvest 

3 6 



metabolism. In essence, we do not expect to change materially our objectives 
but rather to extend their scope. Special areas which we feel will be enhanced 
by additional facilities include plant breeding, plant physiology, plant pathology, 
entomology, and food technology. 

At present we have a vital plant breeding program at Aberdeen in co- 
operation with the Agricultural Research Service of USDA. The aim, for 10 years 
or more, has been to develop a long russet-type potato of quality with resistance 
particularly to leaf-roll and verticillium wilt. Progress has been made, but it 
has been impeded by a lack of facilities by which such things as quality, including 
processing quality can be assayed. While the industry has cooperated fully, 
much additional basic as well as applied research is needed to serve an expanding 
major industry. 

Through use of controlled refrigeration units, as well as growth chambers 
regulated within narrow limits respecting light, temperature, and humidity, such 
things as post-harvest changes in tubers, physiology of sprout inhibitors, changes 
in vitamin content, and texture of cooked and processed products can be carefully 
studied. There is a definite need for this type of research. 

Believing that insects and diseases behave differently on potatoes according 
to season, plant, and environmental conditions, it seems logical to suspect that 
some knowledge of limits of epiphytotics and/or infestations might lead to better 
disease and insect control. Host- paras ite relationships may be better studied 
under controlled conditions. This is particularly true with a disease like 
verticillium wilt, in which these relationships are not well understood, or in 
Rhizoctonia solani where nitrogen and phosphate fertilizers play an apparently 
important part in stem canker development. One can apply this same perspective 
to work with viruses and nematodes. 

This is the picture today. The potato industry is so vital that no one can 
say today what kind of research will be needed tomorrow. Planning is essential, 
but if changes in plans are needed, it is well to be abreast of the situation. We 
believe we can serve Idaho's present and future potato research needs with the 
new facility and those presently available. 



EVALUATION OF POTATO VARIETIES FOR THE SLOUGHING 
AND TRANSLUCENCY OF DICE FOLLOWING FREEZING DURING PROCESSING 



C. E. Cunningham, Campbell Soup Co. , Riverton, New Jersey 
R. V. Akeley, U.S. Department of Agriculture, Beltsville, Maryland 
and T. E. Snyder, Campbell Soup Co. , Riverton, New Jersey 

Diced potatoes may slough excessively or become translucent when 
subjected to the processes involved in the preparation of frozen potato soup. 
Potatoes that exhibit either of the tendencies excessively do not meet finished 
product standards. Varieties grown in Maine, New Jersey, Ohio and Wisconsin 
in 1962 and 1963 were subjected to a standardized processing procedure after 
harvest and at intervals following storage at 40 ° , 45° and 55 ° F. to determine 
the tendency of their dice to slough or to become translucent. 

Sloughing was affected by variety, location, season, storage temperature, 
and length of storage. It increased with prolonged storage at 40 °F. When 
potatoes were processed in January, sloughing was greater following storage at 
45* or 55° than at 40 " . 

Microscopic examination of tissue from samples of translucent and non- 
translucent dice revealed differences in the appearance of cells. Cells from 
nontranslucent samples were opaque, whereas those from translucent samples 
appeared clear. Translucency also was affected by variety, location, storage 
temperature and length of storage. Translucency increased during storage at 
40° until mid- January. When processed in late March, translucency ratings 
of samples stored at 40° were similar to those of January while translucency 
appeared to decrease in samples stored at 45 ' . 



STABILITY OF FROZEN FRENCH FRIES AT REFRIGERATOR TEMPERATURES 

Frank P. Boyle, George K. Notter, H. David Michener and D. G. Guadagni 
Western Regional Research Laboratory, USDA, Albany, California 

Frozen French fried potatoes are produced in greater quantities than any 
other frozen vegetable. Out of a total of some 700 million pounds produced annually, 
two-thirds are destined for the institutional market -- restaurants, hospitals, etc. 
Even though these "par fries" are produced and warehoused as a frozen product, 
it has been reported that some small restaurants and drive-ins, lacking freezer 
space, hold their supplies in a refrigerator. To test the effects of such handling, 
commercially made par fries were held at 3 temperatures above freezing -- 35°, 
45° , and 55 °F. 

Chemical, physical, bacterial, and taste-panel analyses were made on these 
fries kept for varying lengths of time at elevated temperature. In each test they 
were compared with par fries from the same lot which had been stored at -Z0°F. 

3 8 



A rapid growtJi of bacteria took place on the par fries held above freezing 
and color, flavor, and texture deteriorated with increased storage. Our limited 
studies on one lot show that, if par fries must be held above freezing, maximum 
storage should be no longer than 3 to 4 days at 55 ° F. , 6 to 7 days at 45 ° F. , and 
10 to 15 days at 35 ° F. 

Since the initial bacterial level of the lot was relatively low, it would 
follow that other lots with higher starting bacterial counts would have even less 
"shelf life" at these temperatures. In no wise should it be construed that holding 
such a frozen product at elevated temperatures is a recommended practice. 



OXIDATIVE AND OFF-FLAVOR DEVELOPMENT IN POTATO GRANULES 

B. Feinberg 

Western Regional Research Laboratory, USDA, Albany, California 

The fat content of potatoes is only about 0. 3 percent on a dry basis. The 
fatty acid content of potato fat is about 75 percent linoleic and linolenic acids, a 
composition similar to that of linseed oil. Because of this high degree of un- 
saturation, off-flavors from oxidative rancidity frequently limit the shelf life of 
dehydrated granules and flakes. Packaging in a nitrogen atmosphere effectively 
retards oxidation but is expensive and difficult, especially in flexible film. Anti- 
oxidants are commonly used, but they have proved to be only partially effective. 

Certain European countries have prohibited the commonly used anti- 
oxidants, BHA and BHT, in dehydrated potatoes. In this country some consumers 
object to unfamiliar food additives. Several attempts have been made to market 
air-packed granules or flakes without nitrogen packing or antioxidants from 
freezer cabinets at 0°F. Rancidity however was found to be a serious problem 
in some lots. 

Investigators have previously reported that for some commodities, such as 
milk powder, fish meal, fish oil, and butterfat, low temperature is not only inef- 
fective but actually results in accelerated rancidif ication. This would mean a 
more rapid reaction rate at lower temperatures, an unusual phenomenon. 

One commercial nitrogen- packed lot of potato granules with an original 
moisture content of 7. 2 percent was adjusted in part to 3. 5 and in part to IZ. 6 
percent moisture. The original granules contained 200-300 ppm. of sodium 
sulfite and 0. 3 percent glycerol monostearate but no added antioxidants. A 
portion of the lot was nitrogen- packed as control, the remainder air-packed in 
6-oz. cans. Samples of the three moisture levels were stored at -20', 0°, 
12°, 40°, and 70 °F. Oxidative off-flavor was followed by organoleptic taste 
panels and measurement of hexanal by gas liquid chromatography. Buttery has 
previously reported that a trained taste panel can detect oxidative off-flavors when 
the hexanal concentrations in the vapor above reconstituted potatoes is about 4 ppm. 



39 



The results show that, for this lot of potatoes, there was no increase in 
reaction rate at low temperatures. The potatoes stored at -20°F. developed 
hexanal and oxidative off-flavors much more slowly than at temperatures above 
12 °F. Potatoes adjusted to 12. 6 percent moisture showed virtually no hexanal 
development at all temperatures although some off-flavors developed. Potatoes 
adjusted to 3. 5 percent moisture oxidized rapidly. These results correlate with 
previously published data for dehydrated vegetables. 

Methods of manufacture or variations in raw material may influence the 
unusual effect of a faster reaction rate at low temperatures. Milk powder has 
been reported to develop off-flavors more rapidly at -20° than at ° C. 
Instantized milk is particularly susceptible to this effect. Menhaden fish meal 
manufactured in the United States oxidized much more rapidly at -20° than at 
25 ° C. , but English workers were unable to find this effect on fish meal made in 
the United Kingdom. 

Some preliminary work with electron spin resonance spectrometry indicates 
that this method might be used to follow the fate of free radicals, which oil chemists 
now believe initiate fat oxidation. The amplitude of the ESR curve at certain 
frequencies is roughly proportional to the concentration of free radicals. Free 
radicals were found in potato granules and potato flakes from four different 
manufacturers. Granules irradiated under ultra-violet light for 12 hours showed 
no increase in the amplitude of the ESR curve. Similarly potatoes stored for 
varying times under different temperature conditions all showed approximately 
the same degree of free radical activity. However, potatoes which had been 
reconditioned from 7. 2 to 12.6% moisture, and which showed virtually no hexanal 
peaks, produced no free-radical signals. 



4 



QUICK- COOKING DEHYDRATED POTATO PIECES BY EXPLOSIVE PUFFING 



Roderick K. Eskew 
Eastern Regional Research Laboratory, USDA, Philadelphia 

It was just three years ago in Orlando, Florida, that mention was first made 
before this group of quick- cooking dehydrated potato dice , made by explosive puffing. 
Pilot plant research has continued actively and the process has now been successfully 
applied to sweet potatoes, carrots, rutabagas, beets, apples, and blueberries. 
Developments of primary interest to this group deal with new potato products made 
by explosive puffing and improvements in gun design and operation that will further 
cormner cialization. 

In the first category are potato slices. The now well-known commercial 
product is hard, brittle, and slow to rehydrate. When used au gratin or scalloped, 
a full hour of baking is generally required to make the pieces tender. In contrast, 
explosive puffed slices, when prepared as directed, require only about 10 minutes' 
baking. The comparative appearance of the two dried products is shown in Figure 1. 

As far back as 18 years ago a representative of a large potato dehydration 
company told me of the need for a stew chunk that could be dehydrated in a reasonable 
time and would rehydrate quickly. I believe we have now achieved this by explosive 
puffing. The pieces shown in Figure 2 can be reconstituted for eating with only 
5 minutes of boiling. The total drying cycle to reduce moisture to about 5 percent 
was 8 hours. The imagination of you who are dehydrators will suggest the time 
that would have been required to dry and to reconstitute cubes of this size, if they 
had not been explosively puffed. Pieces of other sizes and shapes can also be made 
by this process. 

But these products are of only academic interest if they cannot be made 
commercially. Cereal puffing guns designed for 15 atmospheres or more have 
low capacity and are ill-suited to the needs of vegetable and fruit puffing. Unlike 
cereals, potato pieces have no integument and their tissue is fragile. The object 
of puffing vegetables is not to create a permanent volume increase of ten-fold or 
more as with cereal, but merely to develop a porous structure which will permit 
rapid evaporation of moisture, later drying and rapid water uptake on reconstitution. 
When reconstituted, the porosity should disappear and the pieces should acquire the 
dimensions of freshly cooked pieces of the same size. 

We recently installed a pilot-plant gun of our own design which permits 
rapid heating of the charge, less heat damage, and greater output than characterized 
earlier models. It is 10 inches in diameter by 30 inches long and will handle a 
charge of approximately 18 pounds of 3/8-inch potato dice containing, for example, 
25 percent moisture. To shorten the cycle we use a combination of external gas 
flame and injected superheated steam. The next few pictures show the gun in loading, 
operating and discharge positions and the chute into which the gun is fired. 
(Figures 3, 4, 5 and 6. ) 




Figure 1. Potato slices (left) have been explosion puff dried; those on right have 
been prepared by conventional dehydration methods. 




Figure 2. White potato pieces, i. 5x1. 5x0. 75 inch, first row (left to right), 

dehydrated to about Z5 percent moisture for puffing; second, explosively puffed 
and dried; third, rehydrated 5 minutes in boiling water (ready to eat). 



The potato season terminated so soon after the new gun became available 
that we have not finally worked out the optimum operating conditions for puffing 
potato pieces. The following conditions, however, give good results. After peeling, 
trimming, sulfite dipping, and dicing by conventional procedures, superficial starch 
is removed by thorough washing. If high- solids potatoes are used, the dice are pre- 
cooked and cooled to prevent sloughing on reconstitution. They are then blanched, 
followed by sulfiting with or without calcium firming. Preliminary drying is carried 
out under conditions common in the industry except that the moisture is reduced to 

4 2 



only about Z5 percent. In order to equilibrate the moisture within and among the 
pieces they are retained at room temperature for several hours in closed containers. 
The minimum tempering time consistent with good puffing is now under study; it is 
probably in the neighborhood of four hours for 3/8 inch dice. After tempering, the 
dice are charged to the preheated gun, the lid is quickly closed and horizontal 
rotation is started immediately. The wall of the gun is maintained by an external 
gas flame at about 350 °F. for about two minutes. This forewarms the pieces to 
prevent condensation of the superheated steam. After this two-minute forewarming, 
superheated steam at about 500 °F. and 60 pounds per square inch is admitted to the 
gun. A small orifice in the lid permits escape of air and a little steam. The gas 
burner continues to supply external heat to keep the wall temperature at 350 °F. 
After about 1 minute, full pressure will have been reached. This is maintained for 
approximately 1-1/ Z minutes, the gas is shut off, the gun is tilted while rotating to 
bring the charge to the muzzle. Rotation is stopped, the gun is fired downward into 
a chute, and the cycle is repeated. 

Under present conditions which do not yet necessarily represent the optimum, 
one gun can handle approximately nine 18-pound charges per hour of 3/8-inch 
vegetable dice containing 2Z percent moisture. This amounts to more than 1-1/Z tons 
per day of finished product. Four guns and two collection chutes installed with 
instrumentation should cost about $45, 000. This capital investment would be largely 
offset by saving in drier capacity, for explosively puffed materials dry approximately 
twice as fast as nonexploded pieces. A 4-gun plant would have a capacity of 
approximately 6-1/Z tons per day of finished product. 

Unlike carrots, which are nearly foolproof, potato pieces require close 
control of operating conditions. The reducing sugars should be below about 1. Z5 
percent on the dry solids basis. Otherwise, discoloration from Maillard type 
reactions will develop during heating in the gun. This can be minimized by use of 
sulfite levels so as to have between ZOO and 300 ppm. in the finished product. 
Uniformity of moisture among and within the pieces is important if all are to be 
well puffed. Clumping in the gun may result if starch has not been thoroughly 
washed from the piece surface or if any condensation takes place during steam 
injection. We have found recently that clumping can be virtually eliminated by 
immersing the blanched pieces in a 0. 5 percent emulsion of a monostearate. Of 
course, as with all vegetables the moisture, pressure, and gun wall temperature 
must be carefully controlled. But quality control is essential in any food processing 
ope ration. 

Our experience to date with potatoes convinces us that it is commercially 
feasible to explosively puff them and obtain unique products at a cost only a little 
above that for conventionally hot-air-dried material. 

Our pilot plant research at this stage is devoted primarily to improving gun 
design and operation, for we believe this will lead most quickly to commercialization. 
Heating externally with gas and internally with superheated steam has proved very 
advantageous but there is always the problem of condensation. We are therefore 
arranging to use hot compressed combustion gases instead of steam. This will not 
only avoid condensation but will shorten the overall cycle by eliminating the necessity 
for forewarming the charge. The net effect should be better color and flavor and 
greater output per gun. 

4 4 



We believe that batch guns are feasible commercially, especially for small 
and moderate scale operation. (Batch operation has been used in the cereal industry 
for 50 years. ) However, we have not overlooked the desirability of a continuous 
puffing gun. In fact a basic unit which we believe can be modified to serve this 
purpose is scheduled for delivery in about 30 days. Meanwhile, much of what we 
are learning with batch guns will be directly applicable to continuous operation. 

What are the prospects for commercialization? We know that there has been 
a very favorable response to many of the thousands of samples of explosively puffed 
fruits and vegetables that we have sent out. Several companies have bought or built 
their own guns -- some probably from our own designs, judging by the numerous 
requests for construction drawings. A plant is reported to be under construction in 
Japan and experimental quantities are being made in Europe. We have seen some of 
the Japanese products and they are excellent. More significant is the fact that 
California Vegetable Concentrates of Modesto is now producing commercial quantities 
of puffed carrot dice by a version of our basic process. The new products are 
selling at a premium over the conventionally dried dice. The company reports better 
flavor retention on storage than characterizes the latter product. 

We can reasonably expect that explosion-puffed vegetable s will become 
increasingly available and will bridge the great gulf of price and quality that lies 
between conventional hot-air-dried and freeze-dried materials. 



STUDIES ON THE RELATIONSHIP OF SPECIFIC GRAVITY 
TO TOTAL SOLIDS OF POTATOES 

W. L. Porter, T. J. Fitzpatrick and E. A. Talley 
Eastern Regional Research Laboratory, USDA, Philadelphia 

The measure of potential processed quality of potato products, probably most 
accepted by industry, is the specific gravity of the raw potato stock. This very 
likely is true because the determination of specific gravity is much easier than that 
of solids. It is high time that the principles of statistical quality control are applied 
to the method of estimating solids by the determination of specific gravity. 

Close examination of the data of Glynne and Jackson (J. Agri. Sci. , 9, 
237-258, 1919) and of Von Schula e_t^al. (Landw. Vers. Sta. , 127, 67-96, 1936) show 
that the range of their individual determinations was as high as H- 2. percent solids 
different from the estimated values they could calculate. This inherent variation was 
recognized much earlier by Behrand et al. (Landw. Vers. Sta. , 25, 107-165, 1880). 
Although not undertaken with this purpose in mind, our studies on the properties of 
five varieties of potatoes, each grown in six locations in 1962 and in 1963, confirm 
the fact that these variations occur. The confidence limits are 1. 53 percent solids 
at the 95 percent level. For instance, there could be a difference of more than 
3 pounds in the yield of chips from 100-pound lots of potatoes having the same specific 
gravity. And differences are indicated "between our results based on American 
potatoes and those of Von Schula based on Scandinavian potatoes. 



45 



The variation of solids for a particular specific gravity cannot be explained 
by differences in the density of solid components of potatoes. But a volume factor 
is involved in the specific gravity determination that is not involved in the solids 
determination. For example, hollow heart would be expected to affect the specific 
gravity but not the total solids determination. (Our results vary from these expecta- 
tions. ) Davis (Amer. Potato J. , 39^, 298-305, 1962), Nis sen (Ibid. , 32_, 332-339, 
1955) and Iritani et al . (48tl-i meeting Potato Assoc. of Amer. , 1964) h'ave attempted 
to correct for dissolved and entrapped air. 

A total of 135 samples is probably too small a segment to use to draw any 
final conclusions or to be used for calculating new tables. More data should be 
collected and correlated, using American potatoes of several varieties, grown in 
the main producing areas of the country. From these data a new regression curve 
could be determined and the range of total solids which we may expect to encounter 
for any one specific gravity could be calculated. 



BIOCHEMICAL FACTORS INVOLVED IN POTATO BLACK SPOT 

F, D. Howard, H. Timm, M. Yamaguchi, and D. L. Hughes 
University of California, Davis 

Black spot of potatoes has been the subject of investigations for 60 years. 
De Bruyn (1) first discovered that the cause is a bruising blow. This enabled 
researchers to evaluate the influence of many factors on susceptibility. In spite 
of this impetus, little is known concerning the mechanism of black spot, although 
some work has been done to identify compounds associated with it (4, 6), This paper 
presents evidence that suggests a relationship between cell membrane response and 
black spot susceptibility. Since cell membranes are prote inaceous, a study was 
conducted to examine whether or not changes in the protein distribution in cortical 
cells occurred during tuber development. 

Materials, methods, and results. The techniques used in producing, scoring, 
and rating black spot have been previously described (2). 

Turgor studies. For these studies newly harvested White Rose tubers grown 
at Davis, Calif., were used. Mature tubers were selected for uniformity of size and 
shape and placed at 20° C. Cores 1 cm, in diameter were removed from each tuber 
from stem to bud end, leaving a space in the center. A rubber stopper plugged one 
end of the hole and to the other a pipette was affixed with molding clay. Various 
turgor states were achieved by adding water or 0.2, 0.4, 0.6, or 0. 8M sucrose. 
The solutions were in contact with the tubers for 4, 22, 24, and 24 hours, respec- 
tively, prior to bruising. For each treatment 20 tubers were used. The black spot 
index for each was calculated from 40 bruisings. Black spot evaluations were made 
4, 22, 51, and 70 hours following harvest. 

Solution movement in the pipette was observed. The level continuously de- 
creased when water and 0. 2M sugar were used, indicating that the tubers were absorb- 
ing the liquid. Tubers in contact with water absorbed 7. 9 ml. in a 24-hour period. 



46 



The level of the solution in the pipettes attached to tubers to which 0.4, 0.6, and 
0. 8M sugar had been added gradually rose, indicating withdrawal of liquid from 
tliese tubers.' Tubers in contact with the 0. 8M solution raised the level of solution 
in the pipette 4. 5 ml. during 24 hours. These tubers were quite soft when bruised. 

Figure 1 compares the bruising response of intact tubers with that of tubers 
in contact with water and 0. 8M sucrose solution. In all cases tlie data show a 
gradual decline in black spot susceptibility with time after harvest. It is apparent 
that tissue with varying degrees of sensitivity to bruising can be selected from the 
same lot of tubers, simply by holding in air for varying times. This criterion was 
used for selecting tubers of differing degrees of sensitivity to bruising in the 
conductivity studies. 

Figure 2 shows the effect of cell turgor on black spot susceptibility of tubers 
held at 20° C. for various intervals following harvest. A general trend toward 
decreased susceptibility with decreased turgor is indicated, as the black spot indexes 
were generally less for tubers in contact with solutions of higher molarity. This 
method of affecting turgor has the advantage over immersion methods that the turgor 
adjustment proceeds under aerobic conditions and hence respiratory processses are 
less likely to be affected. 

Conductivity studies. Conductivity was measured with an industrial instrument, 
conducting-br idge Model R. C. Samples containing 10 grams of cortex tissue cut into 
1-cm. discs were placed in 50 ml. of distilled water. Readings were taken on the 
ambient solution at intervals. The data are expressed in electrical conductivity units. 
For converting conductivity readings from milliohms/ cm. (E C X 10-^) to ppm, salt, a 
factor of 640 may be used as an approximation. 

For the susceptible tissues, samples were taken from a lot of newly harvested 
tubers with a black spot index of 550. For the nonsus ceptible tissues, samples were 
taken from the same lot as above except that these tubers were kept in air for 70 hours 
prior to bruising and had a black spot index of 100 (2). The tubers were bruised and 
then samples were taken from the bruised area. Nonbruised tissue samples were 
used as controls. 

Data on bruised and nonbruised tissues from susceptible and nonsus ceptible 
tubers (Figure 3) indicate that the bruised tissues susceptible to black spot effect 
a rapid increase in electrical conductivity of the ambient solution. The bruised non- 
susceptible tissues behaved like the controls and very little ion leakage was detected. 
This indicates that ion movement freely occurs following a bruise in susceptible 
tubers and not in nonsus ceptible tubers. The data suggest tliat membrane rupture is 
a prerequisite to black spot formation. 

The effect of CO^ on susceptibility of White Rose tubers to black spot has 
been reported (3). It is of interest to note tlie effect of CO^ on the conductivity of 
nonbruised tissue. The behavior of this tissue was similar to tliat of the bruised 
susceptible tissue. The evidence implicates eitlier tlie cell wall or the tonoplast 
(vacuolar membrane) with black spot susceptibility. The cell wall is the first 
structure to receive the force of a blow. For black spot to develop tliis force must 
be transmitted to the vacuole where either altered permeability or membrane 
rupture (tonoplast) occurs, thus producing conditions necessary for black spot to 

4 7 



500 




10 20 30 4 50 60 

HOURS AFTER HARVEST 



70 



EFFECT OF CELL TURGOR ON BLACK SPOT INDEX 



500 



400 



X 

UJ 



O 

CO 

i<£ 
O 
<I 



300 



200 



100 







4 22 51 70 4 22 51 70 4 22 51 70 4 22 51 70 4 22 51 70 
HOURS HELD AT 20° C 
0.0 0.2 0.4 0.6 0.8 

% SUCROSE SOLUTION 

Figure 2. The effect of turgor on stem end bruising of tubers held at 20° C for 
various intervals following harvest. 



develop. If, on the other hand, the force received by the cell wall is dissipated in a 
manner not affecting the vacuolar membrane, then black spot will not develop. Thus, 
the cell wall may play an important role in black spot susceptibility. Of equal 
importance is a possible role of the vacuolar membrane as this structure must be 
affected for black spot to occur. It appears that CO^ affects permeability of this 
membrane and in this way bears a relationship to black spot susceptibility. 



48 




Black spot can also be induced by sonic vibrations. These presumably 
rapture the membranes, presenting conditions similar to those obtained by bruising. 

Growth regulator experirnent. For this experiment potato plugs from the 
stem end, containing only cortex tissue were used. The plugs were floated in dif- 
ferent concentrations of various growth- regulating compounds for one hour. They 
were then removed, blotted dry and allowed to stand in air for 24 hours. Then the 
tissues were examined. In considering the mechanism of auxin action, these 
compounds are suspect in relation to changes in properties pertaining to the cell 
wall and the membranes, especially in respect to extensibility and permeability 
(4, 5). Therefore the action of several growth regulators was tested on potato 
tissues. Those soaked in IC^M lAA turned dark giving the appearance of bruised 
tissues showing black spot even though the tissues were not bruised. None of the 
other chemicals showed any observable effect. They included lO'^^M lAA, 10" lAA, 
10"^M IBA, lO'^^M IBA, 10"^M IBA, 10"-^M iodoacetate, lO"^ iodoacetate, 10"^ 
iodoacetate and control. 

Protein and amino acid analyses. White Rose tubers were harvested from a 
plot at Davis immediately prior to analysis. The plot contained two moisture levels 
(0.5 and 1.5 bar, moisture tension) and three levels of nitrogen (120, 240, and 480 
lbs. N/acre) and was replicated three times. 

Cortex tissue was removed from the stem end of ten tubers for each sample. 
Duplicate two-gram samples were placed directly into a Kjeldahl flask for total 
nitrogen determination. One hundred grams of tissue were placed in a blender with 
an equal volume of 1 percent NaCl, and filtered through chee se clotli. The filtrate 
(40 ml.) was centrifuged at 37, 000 x G for 30 minutes. Particulate nitrogen was 
dstermined on the precipitate from the high-speed centr ifugation. Five ml, of 
the supernatant was transferred to a 15-ml. centrifuge tube together with 5 ml. of 



49 




Figure 4. Effect of moisture and 
nitrogen level on distribution 
of nitrogen in cortical cells of 
tube r s . 



74 88 104110 54 74 88 104 110 54 74 88 I04II0 



DAYS AFTER PLANTING 
120 240 

NITROGEN - LBS /ACRE 



480 



20 percent trichloroacetic acid (TCA) for total protein and free amino acid determina- 
tion. The precipitate was transferred to Kjeldahl flasks for determination of the 
soluble protein and the TCA soluble fraction was used for free amino acid determina- 
tion. 



Once entry into a cell is gained nearly all of the nitrogen becomes localized 
either in proteins or as amino acids. The protein nitrogen can either be bound to 
or become a part of larger particulate structures or remain in smaller units in the 
cytoplasm. For this study the term particulate N is used to include nitrogen bound 
as protein to th.e various particulates or organelles within the celL Structures 
included are nuclei, mitochondria, golgi bodies, and sphaerosom.es. Ribosomes are 
also organelles, but because the differential separation was made at 37,000 x G, they 
were included with the soluble proteins which remained in solution following this 
treatment. Free amino acids were separated from the soluble proteins with TCA 
as they are not precipitated with this reagent. 

Figure 4 shows the distribution of nitrogen in cortex cells from the stem end 
of potato tuber tissue. This particular tissue is especially responsive to a bruising 
treatment, and therefore was selected for this study. The data show that the 
irrigation treatments (wet and dry) had very little effect on the distribution of 
nitrogen in these cells. 



The sum of the particulate, soluble and free amino acids approximate the 
total N value for any given sample. Some variations can be noted (Figure 4) and are 
reasonable in view of the fact that the assays were made on separate samples. 
Notable variation is apparent with the total N values at the high N level. In general, 
good agreement was obtained and serves as a valid check on the tissue separation 
technique for determining the nitrogen distribution. 

50 



Particulate N remained at a fairly constant level after the plants were 88 days 
old regardless of treatment. The soluble protein N increased to a high at 104 days 
and then began to decrease slightly at harvest time. Again the pattern was only 
slightly affected by the stress treatments of moisture and nitrogen applied to tlie 
plants during growth. The free amino acids followed a pattern generally similar to 
that of the soluble protein and was not seriously affected by the treatments. It 
appears that the cells are capable of achieving a given balance of nitrogen distribu- 
tion in spite of extreme differences presented to the plant during growth. 

The treatment differences were intended to provide the conditions necessary 
to produce tubers with widely differing responses to bruising. However, this was 
not the case as is indicated by the black spot indexes shown in Table 1. It is difficult 
therefore to make valid conclusions from these data between black spot response and 
the distribution of nitrogen in the cortical cells of potato tubers. 



Table 1, Influence of two irrigation treatments (wet and dry) and three nitrogen 
levels on black spot index of newly harvested White Rose tubers. 



Days 
after 




Wet 






Dry 




Lbs. 


nitrog 


en/ acre 


Lbs. 


nitrogen/ 


acre 


harvest 


120 


240 


480 


120 


240 


480 








Black spot indexes 






92 


82 


25 


73 


22 


39 


10 


104 


70 


94 


78 


48 


58 


59 


110 


63 


123 


68 


56 


114 


104 


114 


65 


58 


41 


12 


44 


16 


Summary, 


Data were p 


resented that indicate 


the fc 


illowing: 


(1) Black spot 



susceptibility decreases with time, following harvest with cell turgor held constant, 
indicating that susceptibility is probably independent of cell turgor. (2) Conductivity 
studies provide evidence that implicates a relationship between the cell membrane and 
black spot susceptibility. (3) Black spot can be produced artificially either by soni- 
cation or by immersing the cells in a solution of lAA which probably exerts its 
influence through altered permeability. (4) No correlations could be found between 
the distribution of N in the cell and susceptibility to black spot 

Literature Cited 

1. De Bruyn, H. L. G, 1929. Het blauw worden den aardappelen (Blue discoloration 
of potatoes). Tijdschrift over Plantenz^iekten _35:185- 222. (English summary) 

2. Howard, F. D. , J. F. Laborde, M. Yamaguchi, and J. E. Knott. 1961. Studies 
of internal black spot of California-grown White Rose potato tubers. Proc. 
Amer. Soc. Hort. Sci. 78:406-412. 

3. Howard, F. D. , M. Yamaguchi, and J.E. Knott, 1963. Carbon dioxide as a 
factor in susceptibility of potatoes (Solanum tuberosum L, ) to black spot from 
bruising. Int. Hort, Sci. Soc. Proc. 584-590. 

4. Jacob, W. C. 1959, Studies on internal black spot of potatoes. Cornell Univ. 
Agr. Expt, Sta, Memoir 368. 86 p. 

5. Leopold, A. C. 1955. Auxins and plant growth, Univ. Calif. Press, 354 pp. 

6. Mulder, E.G. 1949. Mineral nutrition in relation to the biochemistry and 
physiology of potatoes. Plant and Soil 2:59-121. 



51 



BRUISING AND TEMPERATURE IN RELATION TO INTERNAL 
DISCOLORATION OF POTATOES 



M, L. Weaver 
Washington State University, Pullman 

The relationship between tuber temperature and internal black spot has been 
studied intensively for the past three years. From these studies there appears to be 
no direct relationship between the two. Lots bruised at temperatures between 35° 
and 95 °F. varied greatly in susceptibility. In general, bruises on cool tubers were 
darker than bruises on warm tubers. There were so many cases, however, where 
the exactly opposite relationship occurred that we must conclude that temperature is 
not a direct cause; it apparently serves as a modifier of black spot susceptibility. 

Since a large part of the potatoes produced in the Columbia Basin of 
Washington are grown, harvested, and shipped during hot weather, the relationship 
between high temperature and bruising has been a matter of great concern. Interest 
was intensified when reports from receivers in eastern markets referred to a dis- 
order called "the black spot that rots to the center. " At first this disorder seemed 
to be soft rot. However, a study of rotted potatoes sent from Washington, D. C, , 
revealed that a rot did appear to penetrate from the bruised areas, and commonly 
known soft-rot organisms were not isolated from the rotted tissue. 

To learn more about this problem, tubers were subjected to temperatures of 
100" and 105 " F. in the laboratory for 24 hours prior to artificial bruising. When the 
tubers were peeled 24 hours after bruising, the injured area was shiny and black, 
quite similar to blackheart. It was noted also that the discolored tissue penetrated 
deeply. Tubers were next exposed to 95° , 100°, and 105 ° F, for different times 
prior to injury to determine if there is a relationship between this penetrating rot 
and blackheart. The development of both blackheart and penetrating rot occurred 
when tubers were exposed to 100 ° F. (38 ° C. ) for 12 hours or 105 ° F. (41, 5 " C. ) for 
3 to 6 hours. In several instances, holding tubers for only 6 hours at 100 "F, or 
merely letting tubers reach 105 "F. prior to bruising was sufficient to cause rot. 
In general, tubers taken directly from the field were very susceptible to high- 
temperature injury. Susceptibility decreased with storage. Penetration of rot from 
the bruised area was rapid. Twenty-four hours after bruising, rot had penetrated 
approximately three-fourths of an inch deep. By the end of 48 hours rot had 
penetrated to the core and had united with the streak of blackheart tissue. In tubers 
held for 96 hours at 75 °F, almost all tissue below the epidermis was rotted. At this 
stage the injury could not be distinguished from organism- induced soft rot. Figure 1 
shows rot penetrating from the bruised areas and uniting with blackheart tissue 48 
hours after injury. 

It has generally been found that to produce blackheart temperatures of tubers 
held in ventilated storages or shipped in ventilated railroad cars must exceed 100 °F. 
for extended periods. In this study, occasional tubers held at 95**F. for 7 consecutive 
days developed blackheart. In no case, however, did the bruised area develop a 
penetrating type of rot when placed under these conditions of time and temperature. 



52 




Figure 1. Russet Burbank tuber held at 105 "F, for 6 hours and then injured at two 
places on the blossom end and at two places on the stem end. The stem end is on 
the left. The tuber was cut 48 hours after injury. 

Tests were undertaken to determine if the effect of bruising on the penetration 
of rot in tubers exposed to high temperature could be reduced by injuring tubers at 
specific intervals following exposure or at different intervals preceding exposure to 
high temperature. In general, panetration of rot in the bruised areas was decreased 
if tubers were injured IZ hours after exposure to high temperature. On the other 
hand, data regarding injury at specific periods prior to subjecting tubers to high 
temperature were extremely variable between lots; but, in most instances, injury 
24 hours prior to exposure did not reduce the incidence of penetration of rot in the 
bruised areas. 

Other studies were conducted to determine if heat damage is cumulative 
during short periods of high temperature. In one trial, tubers were subjected to 
105 °F. for one hour and then injured. To determine if the temperature effect could 
be reversed, half of the tubers were dropped into ice water at 35 "F. for 30 minutes. 
The other half in each lot were left on the lab bench at 75 °F. None of the tubers 
dropped into ice water and 70 percent of those left at room temperature developed 
blackheart. If tubers were subjected to 105 °F. for one hour in each of two con- 
secutive days prior to injury, 60 percent of those placed into ice water and, again, 
70 percent of those left at room temperature developed blackheart. Exposure to 
105 " F. for one hour in each of four consecutive days prior to injury was sufficient 
to cause blackheart in 100 percent of the tubers. Under this treatment, ice water 
did not reduce blackheart. 

Other workers have produced blackheart by exposing tubers to 100" to lll'F. 
for 15 to 24 hours. When tubers were placed into a low-oxygen atmosphere, black- 
heart developed at much lower temperatures than previously stated. To test the 
effect of oxygen on the penetration of rot from bruised areas, tubers were taken from 
storage and placed into either pure oxygen or normal oxygen levels at 75 "F, for 
eight days. After this period, tubers were exposed to 105 ° F, for six hours and then 
bruised. Ons half of the tubers in each lot were placed into pure oxygen for an 
additional 12 hours. The other half were held at normal oxygen levels. Seven days 



53 



after injury, the tubers in each sample were cut and examined. Tubers held in pure 
oxygen both before and after bruising did not develop blackheart. They did, however, 
have some penetration of rot in both the stem and blossom ends. Tubers held at 
normal oxygen levels prior to and following injury were completely rotted away by a 
combination of blackheart and penetrating rot. Tubers held at normal oxygen levels 
prior to exposure to high temperature and then placed into pure oxygen after bruising 
developed considerable blackheart and penetrating rot, but it was not as severe as 
when tubers were left at normal oxygen levels both prior to and following bruising. 
Sixty percent of the tubers held in oxygen prior to exposure to high temperature and 
placed into normal oxygen levels after injury developed blackheart. One hundred 
percent of the tubers held under these conditions developed the penetrating type of 
rot in both the stem and blossom ends. 

The results suggest that the penetrating type of rot caused by bruising tubers that 
had been exposed to high temperature was similar to, if not identical with, blackheart. 
The bruise evidently triggers reactions at the surface of the tuber that usually occur 
in the core of uninjured tubers subjected to high temperature. 



FACTORS AFFECTING SLOUGHING OF POTATO TISSUE 

Mary V. Zaehringer, Helen H. Cunningham, and Duane Le Tourneau 

University of Idaho, Moscow 

Sloughing in potatoes is the disintegration, cracking, and flaking of tuber 
tissue during processing or cooking. Under application of heat and moisture, starch 
granules within the cells swell and gelatinize. As a result of this pressure, individual 
cell walls may round off and separate, or slough. Cell separation is caused by a 
weakening of the intercellular cementing substances, which are chiefly pectic. In 
addition, other factors are associated with sloughing, including variety, specific 
gravity, storage, size of tuber cells, dry matter, starch, amylose, pectic materials, 
alcohol- insoluble solids, ash, percent total magnesium, total potassium, and alcohol- 
insoluble potassium. 

For the most part, observations concerning sloughing have been made on 
potato tissue in original, unaltered state. However, the fortuitous discovery during 
an earlier study at the Idaho station, that it is possible to decrease sloughing by 
soaking in distilled water and to increase it by cooking in "soak" water seemed to 
offer a new approach to better understanding of the basic factors involved. 

Our first investigations, reported in the October, 1963, issue of the American 
Potato Journal, showed: (1) that sloughing decreased directly with length of soak 
period, with temperature during soaking, and with volume of water used in soaking; 
and (2) that using the water in which the potatoes were soaked as part of the cooking 
water increased sloughing in both soaked and unsoaked tissue slices. The effective- 
ness of the "soak" water in inducing sloughing increased with increase in length of 
soak period, with increase in temperature during soaking, with increase in amount 
of surface area exposed during soaking, and with increase in the ratio of soak water 



54 



to distilled water used for cooking. Soak water prepared from potatoes of high 
specific gravity was more effective than soak water from potatoes of low specific 
gravity in causing sloughing. We have advanced the hypothesis that decrease in 
sloughing of soaked tissue might be caused, at least in part, by diffusion of one or 
more constituents into the soak water. 

The more recent work of Mr, William Davis, reported last week by 
Dr, Le Toarneau, indicated that sloughing is related to high concentrations of the 
following tuber constituents: total solids, ash, alkalinity of ash, potassium, 
magnesium, phbsphorus, and possibly citric acid. As the soak period increased, 
there was a parallel decrease in sloughing which appeared to be related to amount 
of solids, ash, 'potassium, magnesium, phosphorus, and citric acid lost to the soak 
water. 

During the past year we have conducted three more systematic studies on 
sloughing, each planned about a factorial design. The preparation and cooking 
procedures were those previously described by ug. In these procedures, 100-g. 
samples of slices 1 mm, thick were prepared from the entire tuber and cooked in 
1200 ml, of boiling distilled water with mechanical agitation to accentuate sloughing 
losses. The unsloughed material was then weighed directly and reported as the 
cooked potato weight (CPW), Although cooking periods need adjustment for variation 
in specific gravity, the cooking time was uniform in any given experiment. We 
have recently modified the method in that we no longer mix or wash the slices in 
distilled water before shaking out the small pieces with the No, 3 sieve. 

The standard procedure for soaking was to place duplicate 100-g. samples 
in Z50 ml. of distilled water for 2 hours at room temperature. When soak water 
was used, it replaced 250 ml. of the distilled water used for cooking. In the first 
study we compared the sloughing of the bud half of the tuber with that of the stem 
half. Three variables were studied in all combinations: (1) The two halves of the 
tuber--the bud half vs, the stem half; (2) two types of tissue--unsoaked vs, soaked; 
(3) three kinds of cooking water- -distilled water, "bud" water, and "stem" water. 
The tubers were of specific gravity 1. 076-1. 079 and had been stored 3 months at 
45 "F. 

The results are set forth in Figure 1. You will recall that the weight of the 
unsloughed material, CPW, is inversely related to amount of sloughing. As in our 
previous studies, soaking significantly decreased sloughing in both stem and bud 
tissue. The unsoaked bud tissue cooked in distilled water, indicated by the white 
bar, sloughed significantly more than the unsoaked stem tissue cooked in distilled 
water. The" same trend was observed in the soaked tissues cooked in distilled water. 
The extent of sloughing in all tissues was significantly increased when soak water 
was used as part of the cooking water. However, the "bud" soak water (black bar) 
was significantly more effective than "stem" soak water (hatched bar) in inducing 
sloughing. -Although the soak waters were not analyzed for leaching of solutes, it has 
been reported that there is more soluble potassium and more acids in the bud end 
than in the stem end of the tuber. 

The second study concerned the effect of three storage temperatures--38 " , 
45", and 52''F.--on sloughing and on effectiveness of soak water prepared from 
potatoes stored at these temperatures in inducing sloughing. The studies were carried 



80 r 



70 



60 



50 



40 



30 



20 



COOKING WATER 
n DISTILLED 

STEM 
■ BUD 



11 



I 



STEM BUD 

SOAKED 



120 



100 - 



80 



20 



STEM BUD 

UNSOAKED 

SRGR. 1.080- 1085 

STORAGE 
TEMPERATURE 
OF POTATOES USED 
FOR COOKING 




-* 45°F 
52° F 



Figure 1. Effect of soak water 
prepared from bud and stem 
halves of tubers on sloughing 
of bud and stem tissue cooked 
in the soak water. 



Figure 2. Effect of soak water 
prepared from potatoes stored 
at various temperatures on 
sloughing of potatoes cooked 
in the soak water. 



I ■ ' ' 

DW 52°F 45''F SBT 

STORAGE TEMPERATURE OF POTATOES 
USED FOR SOAK WATER 

out on soaked tissue slices prepared from tubers of specific gravity 1. 080-1. 085 
stored for 3 months. Figure 2 shows that tissue from potatoes stored at 45° and 
52 °F. sloughed significantly more than tissue from those stored at 38 "F. Those 
cooked in "soak" water sloughed significantly more than those cooked in distilled 
water. The soak water prepared from potatoes stored at 38° F. was significantly 
more effective in inducing sloughing than those from potatoes stored at 45° or 52 °F. 
This effect was greatest on potato tissue from 38 °F. storage. Although no extensive 
chemical assays have yet been made on these soak waters, preliminary work indi- 
cates that the 38 °F. soak water contains more reducing sugars than 45° or 52 °F. 
soak water. Therefore it is possible that sugar and/or some other metabolite 



56 



developed at low storage temperatures may be a factor in tlie differential sloughing. 

The third experiment, a study of the sloughing of blanched vs. unblanched 
slices, was carried out on potatoes of specific gravity 1. 091- 1. 094 stored for 11 
months at 45**F. The procedure was as follows. Duplicate 100-g. samples were 
blanched for 60 seconds in beakers containing Z50 ml. of boiling distilled water. 
Then the beakers were removed from the heat and placed in an ice-and- water bath. 
Additional ice was placed directly into the beakers to insure rapid cooling. About 
4 minutes was required to bring the samples to room temperature; then the beakers 
were removed from the ice-and-water bath and the unmelted ice was removed from 
the blanch water in the beakers, 

K the potato tissue slices were to be soaked prior to cooking, the slices were 
allowed to stand in tlie beakers of water for the standard Z-hr. soak period. If the 
slices were to be cooked unsoaked, they were drained according to the standard 
procedure and the blanch water was used as part of the cooking water. Thus no 
constituents of the tissue were lost; they were present in either the tissue or the 
cooking water. The differences in sloughing among the samples can therefore be 
fully attributed to the treatments applied. 

In this study the following three tissue treatments were studied in all 
combinations: (1) blanched vs. unblanched; (Z) unsoaked vs, soaked and (3) as 
cooking water- -distilled water, soak water from unblanched tissue, and soak water 
from blanched tissue. Figure 3 shows that, as usual, soaked tissue sloughed 
significantly less than unsoaked. Blanched tissue sloughed significantly less than 
unblanched. Potato tissue cooked in distilled water (white bar) sloughed less than 
that cooked in soak water. Soak water prepared from blanched tissue (black bar) 
was significantly more effective in inducing sloughing than soak water from un- 
blanched tissue (hatched bar), A comparison of the mean cooked potato weight when 



Figure 3. Effect of soak water 
prepared from unblanched and 
blanched potato tissue on 
sloughing of unblanched and 
blanched tissue cooked in the 
water. 



SP GR. 1.091 - 1.094 



COOKING WATER 
n DISTILLED 
V\ UNBLANCHED 




BLANCHED UNBLANCHED BLANCHED UNBLANCHED 
SOAKED UNSOAKED 



57 



soaking and blanching were applied to separate samples with the mean cooked potato 
weight when soaking and blanching were applied to the same sample, indicates that 
the effects of blanching and soaking were almost, but not quite, additive. It is 
possible, therefore, that blanching, in addition to enhancing the leaching of constituents 
(as seen from the differential effect of the soak waters) may have a secondary effect 
on the physical properties of the tissue itself. 

I would also like to mention a preliminary study in which we compared 
sloughing of outside tuber tissue with that of inside tissue. Our data indicate that 
while sloughing of outside tissue was considerably greater than of inside tissue, 
there was no difference in effectiveness of the soak waters from the two tissues in 
inducing sloughing of tissue prepared from the entire tuber. 

To sum up I might say that these studies offer additional evidence in support 
of our hypothesis that the decrease in sloughing of potato tissue on standing in 
distilled water results from the diffusion of one or more constituents into the soak 
water. To date our data suggest tliat at least one of the constituents is soluble. 
At least one is present in the bud half of the tuber in greater amounts than in the 
stem half, but inside and outside tissues probably contain about equal amounts of 
the soluble factor. At least one sloughing factor may be a metabolite developed at 
low storage temperatures. 



EFFECTS OF STORAGE TEMPERATURES OF RED RIVER VALLEY 
POTATOES ON FLAKE QUALITY 

Nicholas Sandar, Red River Valley Potato Research Center, 
USDA, East Grand Forks, Minn. 
A. M. Cooley, University of North Dakota, Grand Forks, Minn, 
and L. A. Schaper, USDA, East Grand Forks, Minn. 



The flake process for dehydrating potatoes is relatively new (1) but is 
extensively used in the USA and other countries. Although numerous studies have 
been made to evaluate the effects of storage temperatures on chipping qualities of 
potatoes (2) information as to how storage temperatures affect flake quality is 
lacking. 

The research reported here studied the effects of storage temperatures on 
quality of flakes ptocessed from several varieties produced under Red River Valley 
conditions. It was initiated in I960 as part of the marketing research activities of 
the U. S. Dept. of Agriculture in cooperation with the Chemical Engineering 
Department of the University of North Dakota. All processing was done in the pilot 
plant at the University of North Dakota. 



58 



Preli minary tests , A preliminary test was conducted with the I960 crop 
using Irish Cobbler, Norland, Kennebec, and Red Pontiac varieties. Shortly after 
harvest the specific gravity, reducing sugars, and sucrose were determined on one 
lot of each and these were processed into flakes. The other lots were placed in 
storage on October 10, at temperatures of 40°, 45", and 55 "F. No sprout 
inhibitor was used. 

The storage period was terminated December 20, because of concern about 
the degree of sprouting in two of the varieties stored at 55 °F. At this time determi- 
nations were made of specific gravity, weight losses, reducing sugars, and sucrose. 
Two sets of reducing sugar data were obtained one at the Potato Research Center 
by the Shaffer-Somogyi method outlined in A. O, A, C, and the other at the University 
of North Dakota by the picric acid method. Each lot was processed into flakes with 
no conditioning after storage. 

As would be expected, varieties differed in specific gravity, but the specific 
gravity was not affected by the storage temperatures. Weight loss was significantly 
lower in the Irish Cobbler than in the other three varieties. Weight loss in all 
varieties averaged nearly 5 percent at 55° F, , about 4 percent at 45 " , and about 
3, 5 percent at 40 " F, Sprouting occurred only in Norland and Red Pontiac stored 
at 55°. The weight of the sprouts accounted for part of the total weight losses for 
Norland and Red Pontiac, 

At relatively low levels of reducing sugar, there was good agreement between 
the Shaffer-Somogyi and the picric acid methods of determination. With high levels, 
encountered from 40 °F. storage, the picric acid method gave consistently lower 
readings. As expected, reducing sugars and sucrose were highest when potatoes 
were stored at 40°, intermediate at 45°, and lowest at 55 °F, Following 55° storage, 
the reducing sugar and sucrose levels were as low as, or lower than, that found 
immediately after harvest, 

A good flake product was made from both the freshly harvested and stored 
lots of all four varieties with no noticeable differences. Some Red Pontiac and 
Norland tubers out of 40 °F, storage exhibited pink centers. The best yield of 
flakes in pounds per minute from the flaker was obtained from Irish Cobbler and 
Kennebec. Temperature effects were not consistent but trends indicated slightly 
better production per minute from the flaker when potatoes had been stored at 55 °F, 

Main tests. Based on the preliminary results, the project was greatly 
expanded in 1961 when four bulk storage bins were remodeled so that controlled 
storage temperature could be provided for extended periods. The Snowflake 
variety replaced Norland and evaluation for processing qualities and other factors 
was based on monthly samples starting in January and continuing until August, A 
control sample was evaluated at harvest. Sufficient quantities of Irish Cobbler, 
Snowflake, Kennebec, and Red Pontiac were stored in each 40, 45, and 50 °F, 
controlled temperature rooms for 8 periodic evaluations. Two one-ton pallet boxes 
of each variety of the 1961 crop were stored in each of the rooms. Fifty-gallon 
steel drums (300 lbs, of potatoes) were used for 1962 and 1963 crops. 

The bottoms of the drums were perforated for improved air circulation 
after problems developed with the 1962 crop. All lots from the 40° and 45 °F, 



59 



storage rooms were conditioned for one month at approximately 65" before flaking, 
except for the January sample lots from the 1961 crop which were flaked and 
evaluated without conditioning. All lots from the 50° rooms were flaked directly 
from storage. Air temperature and relative humidity were recorded by hygro- 
thermographs. Weight and specific gravity changes were determined at the beginning 
of storage and periodically thereafter until conclusion of storage. 

After initial curing, in all 3 storage seasons, temperatures were maintained 
very close to the desired level until the end of April. Then temperatures rose and 
averaged 56 °F. in all three rooms for the remainder of the 1961-6Z season. 
Modifications for 196Z-63 made it possible to maintain an average of 45°, 48°, and 
54° in the 40°, 45°, and 50° rooms respectively after May 1, but this was still 
too high. Thus, identification of 1961 and 196Z lots by storage temperature does 
not always indicate the true conditions. In the 1963-64 season temperatures have 
been effectively maintained at the desired level to date. Pulp temperature of the 
tubers at removal from storage just prior to processing the 1963 crop was very 
consistent at about 59 °F. in the conditioned potatoes and about 50 °F, for those 
from 50° storage. 

Air temperature variations measured by thermocouples inside the storage 
barrel were found negligible in the three controlled rooms. This was not so in the 
conditioning room with a gradient of 4° - 6°F, between air temperatures at the top 
and the bottom of the barrels. This could be explained as air stratification plus the 
fact that the steel barrels rested on a concrete floor common to all four controlled 
rooms, and the differences between air and floor temperatures were greatest in the 
conditioning room. 

Relative humidity has been very variable, ranging from 60 to over 90 percent 
but generally in the range of 70 to 80. Conditioning room temperatures were 
maintained close to 65 °F. with relative humidity generally below 50 percent. 

Sprout inhibitor was used for most lots. For the 1961 crop, only the 45* and 
50 °F. storage lots were treated with C. I. P. C. which effectively controlled sprouting 
Some sprouting occurred following conditioning of the untreated lots from the 40° 
rooms. In 1962 the potatoes stored at 45° and 50° were treated with C, I, P, C, by 
dusting the top layers in the barrels. This controlled sprouting in the top half of 
the barrels, but the bottom half, in many cases late in the season, was a solid 
interlaced mass of tubers and sprouts. All lots from the 1963 crop were treated 
by vaporizing C. I. P. C. into the barrels; sprouting has been effectively controlled 
in most of the treated lots. The application of C, L P. C. to lots in the 50° room 
was delayed and sprouting is currently quite extensive in the Pontiac variety and to 
a lesser degree in the Kennebec. Some internal sprouting is also evident, which is 
most severe with Pontiac, 

The process for flaking varied slightly from year to year, but followed the 
general procedures outlined by Cording et al, (1), Precook time was 20 minutes at 
160° to 165 °F. Cooking time depended on varieties and varied from 20 to 30 
minutes. For the 1961 crop, each 40-pound lot of mash received 10 grams of 
Myverol (Type 1807, containing glycerol monostearate and hydrogenated cottonseed 
oil), 1 gram Tenox IV (containing 20 percent butylated hydroxyanisole, 20 percent 
butylated hydroxytoluene, and 60 percent cottonseed oil), and 6 grams of sodium 



60 



bisulphite. For 196Z, the Myverol was increased to 15 grams on lots processed 
after the middle of February. For the 1963 crop, the Myverol remained at 15 grams, 
bisulfite was reduced to 4 grams, and sodium acid pyrophosphate (SAPP) at 3 grams 
replaced the Tenox. The single drum dryer was operated at a pressure that 
generally varied from 60 to 70 PSIG and at a speed that varied from 2 to 3 RPM, 

Results: In the results presented in Tables 1 to 3 data on harvest conditions 
are single determinations. All others are an average of the monthly determinations 
from January to the end of July. Data for 1963 include an average of only 6 deter- 
minations, with 2 more to be completed. The storage temperatures did not affect 
the specific gravity of the potatoes (Table 1), confirming the preliminary results 
with the I960 crop. Most of the specific gravity readings at harvest were higher 
than those following storage. 

The pounds of flakes produced per minute from the flaker (Table 2) were 
largely dependent on variety used and directly on specific gravity. Since specific 
gravity was not affected by storage temperatures (Table 1) production of flakes per 
minute was also unaffected by storage temperature, Irish Cobbler and Snowflake 
had the highest flake yield par minute, followed by Kennebec, with considerably 
lower rates from Red Pontiac. Yields of flaJkes from the 1963 crop were also 
dstermined on the percentage basis relating weight of dried flakes to weight of 
mash just before drying. The yields were directly related to specific gravity with 
bast yields from Irish Cobbler at 22, Snowflake at 21.7, Kennebec at 21,6 and Red 
Pontiac at 19.4 percent, closely following specific gravities listed under the 1963 
column in Table 1, 



Table 1. --Specific gravity, determined by method outlined by Fdgar (4), of crops 
stored at different temperatures. (Averages of monthly readings from January 

through July.) 

Storage Storage 





Temp, ("F) 


1961 


1962 


1963 


Avg. 


Irish Cobbler: 


Harvest 


1.092 


1.086 








40 + Cond, 


1.086 


1,084 


1.095 


1.088 




45 + Cond. 


1.086 


1.083 


1.093 


1.087 




50 


1.091 


1.082 


1.093 


1.089 


Snowflake: 


Harvest 


1.086 


1.087 








40 + Cond, 


1.083 


1.084 


1.088 


1.085 




45 + Cond, 


1.083 


1.085 


1.085 


1.084 




50 


1.084 


1.083 


1.085 


1.084 


Kennebec: 


Harvest 


1.087 


1.087 








40 + Cond. 


1.083 


1.081 


1.088 


lo084 




45 + Cond, 


1.084 


1.080 


1.084 


1.083 




50 


1.085 


1.080 


1.091 


1.085 


Red Pontiac: 


Harvest 


1.072 


1.078 








40 + Cond. 


1,070 


1.072 


1,079 


1.074 




45 + Cond. 


1.069 


1.073 


1.078 


1.073 




50 


1.073 


1.073 


1.079 


1.075 



61 



Table 2. --Average production of flakes (lbs. per minute) from k varieties stored at 
different temperatures. (Average of monthly results from January through July, 
1961 - 1963. ) 



Storage Temp. (°F) 


Irish Cobbler 


Snowf lake 


Kennebec 


Red Pontiac 


Avg. 


4-u + conci a 


i . iU 




I.Vj 


OA 

.00 


1 .03 


45 + Cond. 


1.07 


1.06 


1.05 


.89 


1.02 


50 


1.13 


1.10 


1.05 


.86 


1.04 


Avg. 


1.10 


1.09 


1.04 


.87 





The moisture content of the flakes was generally near 6.5 percent with a 
low of 5. 5 and a high of 7. 3. The slight variations appear to be a function of 
process variables rather than a result of storage temperatures or variety. Thick- 
ness of each lot of flakes made from the 1963 crop was measured. Flakes from 
Irish Cobbler and Snowflake were thickest, generally between 0. 006 and 0. 0065 
inch, Kennebec flakes were between 0. 0055 and 0. 006, and Red Pontiac flakes 
averaged about 0. 005 inch. Storage temperatures appeared to have no effects on the 
thickness of the flakes. 



Table 3. --Average reducing sugars (dry weight basis) of k varieties of three crops 
stored at different temperatures (average of monthly determinations from January 
through July). (Reducing sugars for I961 and 1962 were determined by the picric 
acid method, for I963 by the dinitrophenol method outlined by A. Frank Ross (3) . ) 

Storage 



Variety 


Temp. CF) 


1961 


1962 


1963 


Avg. 


Irish Cobbler: 


Harvest 


0.84 


1.01 








40 + Cond, 


1.39 


1.14 


0.97 


1.17 




45 + Cond. 


1.24 


0.94 


0.90 


1,03 




50 


1.87 


0.95 


0.77 


1.20 


Snowflake: 


Harvest 


1.70 


0.94 








40 + Cond. 


2.72 


1.43 


2.35 


2.17 




45 -;- Cond. 


1.89 


1.11 


0.89 


1.30 




50 


2.74 


1.05 


0.95 


1.58 


Kennebec : 


Harvest 


1.53 


0.74 








40 -^ Cond. 


1.35 


0.66 


0.91 


0.97 




45 + Cond. 


1.19 


0,87 


0.73 


0.93 




50 


1.27 


0.71 


0.73 


0.90 


Red Pontiac: 


Harvest 


1.90 


1.59 








40 + Cond. 


3.63 


2.01 


3.91 


3,18 




45 + Cond. 


4.11 


2.14 


2.50 


2.91 




50 


5.02 


1.73 


1.29 


2.68 



62 



Reducing sugars of all varieties of the 1961 crop were considerably higher 
than those for the 196Z and 1963 crops (Table 3). Excessive rainfall just before 
harvest in 1961 may have contributed to the high sugars. It was severe enough to 
cause extensive surface cracking of Pontiac, a variety generally susceptible to 
shattering when turgid under high moisture conditions. For the 1961 crop, only 
the Kennebec variety had reducing sugars, after storage, that were below the 
level found at harvest. Reducing sugars of the other three varieties were very 
high after 50 °F. storage. Conditioning the lots from the 40° and 45 "F, rooms 
resulted in reducing sugar levels similar to or below those of lots stored at 50 "F. 
without conditioning. 

Generally, with the 1962 and 1963 crops, continued storage at 50 "F. gave 
the most consistently low levels of reducing sugars. The Red Pontiac and Snowflake 
varieties had the highest level of reducing sugar in the raw material and this was 
also the case with the finished flake. It is noteworthy that the Snowflake variety 
conditioned well from 45 'F. storage but failed to do so in all three years when 
stored at 40 "F, Continued storage at 50 "F. also resulted in less sprouting than 
occurred when lots from 40° and 45 °F. storage were conditioned. Reconstituted 
flakes of all 4 varieties of the 1961 crop were satisfactory throughout the entire 
period of storage from January to the end of July. Irish Cobbler had a tendency to 
gray as did Snowflake, 

Excessive sprouting and severe decay of the 1962 crop occurred in the 
barrels during May to July and quality of flakes was adversely affected. Decay 
occurred in some barrels in May, but was of real concern with lots processed 
during June and July, Careful trimming and elimination of affected tubers did not 
remove off flavors carried into flakes. Texture was also adversely affected but 
this could be controlled by greater amounts of Myverol, The decay was attributed 
to high temperatures resulting from lack of adequate ventilation since these drums 
were not perforated, plus the fact that excessive sprouting in the bottoms of 
barrels interfered with normal gravity ventilation, Sound tubers of such affected 
lots were dehydrated but these generally resulted in a gray mash even with 
addition of SAPP, The specific gravity of tubers from these heated lots was 
significantly reduced. 

Flakes made of all four varieties of the 1963 crop have been satisfactory to 
date. Early in the season, off flavors were detected in Snowflake, apparently the 
result of a soil chemical used in the production of this lot. The off flavors disap- 
peared after February, and Snowflake has made acceptable flakes since, Irish 
Cobbler and Kennebec have shown a slight tendency to gray, while Red Pontiac has 
consistently made a very acceptable flake. 

Summary and conclusions. After preliminary studies in I960, four varieties 
of potatoes of the 1961, 1962 and 1963 crops were stored under controlled temperatures. 
Lots were evaluated periodically for changes in weight, specific gravity and reducing 
sugars, before processing into flakes. The processing period extended from 
January until the end of July of each year. 

The controlled storage temperatures were 40" and 45 °F, witli conditioning 
at about 65° for one month, and 50° with no conditioning period. Flakes were 
made from a few lots of potatoes stored at 40° and 45° without conditioning. In 



63 



storing the 1961 and 1962 crops, temperatures were not controlled at the desired 
levels after about May 1. With modifications, effective temperature control was 
provided for the 1963 crop. These selected storage temperatures had no effect on 
specific gravity, production of flakes per minute from the flaker, or the percent 
yield of dried flakes. Production and yield were related to the specific gravity 
and thus to variety. 

Reducing sugars were lowest in the Kennebec and Irish Cobbler and 
relatively high in Snowflake and Red Pontiac varieties. Irish Cobbler and Kennebec 
conditioned well out of 40° and 45 ° F. storage, and the reducing sugar level was 
not greatly different from that found after storage at 50". Snowflake conditioned 
well out of 45° storage, but not out of 40°. As expected, reducing sugar content 
of Red Pontiac remained high after conditioning. 

Acceptable flakes were made from all four varieties during the three storage 
seasons regardless of temperatures as long as the tubers were physically sound 
and free of excessive sprouting. Flakes made from the few lots of the 1961 crop from 
40" and 45° storage without conditioning had considerably higher reducing sugar 
levels than flakes from lots that were conditioneda Such high levels are undesirable 
since they affect storage life of the flakes. Development of severe decay in some 
of the storage containers {196Z crop) created problems of off-flavors, gray color 
and poor texture in flakes. This type of problem could be minimized by the use 
of effective inhibitors to prevent sprouting during long storage at higher temperatures 
or during conditioning of potatoes which had been stored at lower temperatures. 

Acknowledgments are extended to H. Findlen and A. D, Edgar, former 
Horticulturist and Agricultural Engineer respectively at the Potato Research Center 
under whose direction the initial work was undertaken; to the Red River Valley 
Potato Growers Association; Borden Foods Co.; Pillsbury Co.; Polar Products 
Inc, ; and to the A. I. D. Committee of Power Suppliers of the Red River Valley, 

Literature Cited 

1. Cording, James, Jr., M, J. Willard, Jr., R, K. Eskew, and P. W, Edwards. 
1954. Potato Flakes: A new form of dehydrated mashed potatoes. ARS73-2, 
Eastern Utilization Research and Development Division, USDA, 

Z, Smith, Ora, 1959. In Potato Pro cessing. AVI Publishing Co. , pp. 234-277. 

3, Ross, A. Frank. 1959, In Potato Processing, AVI Publishing Co, , pp. 469-470, 

4, Edgar, A. D. 1951. Determining the specific gravity of individual potatoes. 
Am. Potato J. 28,729-731. 



64 



IMPROVING FIRMNESS AND TEXTURE OF FRENCH FRIED POTATOES 



Ora Smith and C. O. Davis 
Cornell University, Ithaca, New York 

Sogginess of French fries is one of the most pronounced problems of the 
industry. This problem is accentuated as storage season is prolonged. The longer 
the slice or any increase in the amount of the pith area, the greater the chances of 
soggier centers. As time lapse increases from the finish fry to comsumption the 
degree of sogginess also increases. Processors want a product that can be "driven 
with a hammer" and not have a tough outer surface. 

This problem is not specific for any given area and has confronted proces- 
sors in all areas sometime during their processing season. In our experiments we 
simulated commercial operations and used various one-, two-, and three- stage 
blanches or dips or a combination of them. The purpose was to find either a 
chemical which could be incorporated into the blanch water or to alter the time- 
temperature blanch that would result in a firmer French fry. 

Under blanching prevents gelatinization in the centers of the pieces and 
complete enzyme inactivation. As blanch time increased the tendency for sogginess 
also increased. When blanch temperatures were altered severely the desired 
texture was not attained. Most processors vary the time and temperature of blanch 
only slightly unless excessive sugar leaching is desired. Manipulations of blanch 
time-temperature slightly improved the firmness but was not sufficient to prevent 
soggy centers. 

Several calcium salts were used as firming agents. Included were calcium 
chloride, calcium citrate, calcium gluconate, calcium acetate and calcium lactate. 
None of these calcium salts improved the firmness of French fries. Calcium 
chloride is used in canned potatoes and tomatoes as a firming agent but when used 
in the blanch water or a dipping solution there is not sufficient time for beneficial 
results in potatoes. Since our treatments had to be applicable to commercial 
operations we could not use a holding tank that would require a long period of time 
for an effective treatment. 

The addition of firming agents, modified starches, gums and alginates to the 
blanch water tended to improve the firmness of the French fry. Some of the 
materials used included Clearjel, Supercol, Guar gum, Methocel H G, Cellulose 
gum, Carrageenan materials and the alginates. The majority of these materials 
have several modified forms for specific uses in various food products. Materials 
with different viscosities were used to determine their applicability for improved 
firmness. 

During our screening tests some materials were found to be undesirable for 
several reasons. Splattering of oil upon immersion of the treated French-fry cut 
was serious with some materials. This resulted from the ability of the materials 
to bind or hold water and when they were placed in hot oil, splattering and excessive 
foaming occurred. Inability of the chemical to adhere to the treated piece when 
placed in the oil was cause for its elimination. The material would move from the 
slice to the frying oil, thus becoming charred in time and probably causing 

65 



deterioration of the oil. The high-viscosity materials, even in low concentrations, 
adhered in too large a quantity on the surface of the piece and were not commerci- 
ally practical due to the excessive carry-over following treatment. Another serious 
objection to some treatments w as the rigid coating formed and upon finish frying 
the internal pressure of the French fry cut would rupture the piece, causing an 
unsalable finished product. None of the treatments with any of the materials in- 
creased the degree of browning. Sodium alginate was one of the most promising 
materials tested. Use of low viscosity gel form resulted in firm French fries. 
The addition of a calcium salt in this material improved firmness to a greater 
degree but it was not possible to prevent precipitation of the material on a continuous 
commercial basis. Modification of the blanch and dip procedure showed that treating 
pieces with alginate in a dip tank following the second-stage blanch (which may have 
dextrose and sodium acid pyrophosphate included) and then dipping in a calcium salt 
resulted in a coating that is formed in a few seconds. A one- or two-minute time 
lapse should follow this prior to the par frying operation. Calcium lactate with a 
high solubility gave better results than calcium chloride or the other previously 
mentioned calcium salts. 

The concentration of low- vis cos ity sodium alginate ranged from 0. Z5 to 
0, 50% (weight/ volume) for 30-90 seconds at a temperature range of 80° to ZOO ° F. 
followed by a 1 to 2% calcium lactate dip for 30 to 60 seconds. In two commercial 
French fry operations this method was employed with a substantial increase in 
firmness over the normal water blanch procedure. Experiments showed that 
processors of two-stage oil -blanched non-frozen French fries could increase the 
firmness with the sodium alginate dip followed by the calcium lactate dip. This 
procedure would be adaptable to most restaurants that utilize the one stage oil 
blanch, followed by draining and then finish frying when needed for consumption. 

Since the problem of precipitation of the material may occur and there may 
be difficulty in maintaining the desired concentration due to carry-over from the dip 
tanks another method was used which increased firmness and avoided precipitation. 
Calcium citrate, which has a lower solubility than calcium lactate, was used. The 
use of the low solubility salts prevents precipitation since the calcium is released 
slower and is not in solution in sufficient quantity to react with the sodium alginate 
to form a precipitate. 

A modification of a coating that has been used in the processed fish industry 
was used. The dip solution contains 4 grams of alginate in 500 ml. of water. One 
tenth of a gram of citric acid was mixed with two and a half grams of sodium 
hexametaphosphate. This was added to the alginate solution followed by a slurry 
of one -half gram of calcium citrate. French fry cuts were dipped in the solution, 
cooled, oil blanched, and frozen. The finish fried-product is considerably firmer 
than the water-treated pieces from the remaining half of the tuber. Modifications 
of this method allow thicker coatings and more rigidity but the texture or periphery 
toughness may be undesirable. 

The firmness appears to be mechanical, since a surface coating is produced. 
The surfaces of treated pieces are not as porous as those of the non- treated pieces, 
and ten minutes after finish frying the treated French-fry cuts retain their rigidity. 
All comparisons were made with water- blanched cuts from the remaining half of the 
tuber. Tubers with a specific gravity of 1. 068 were used. Late in the processing 



66 



season biological changes within the tuber occur that cause the pith areas to become 
extremely soggy when fried. Specific gravity of these areas also declines during 
this time. 

Procedures for improving firmness have been outlined but some modifications 
may be necessary to fit a particular processing line. Further studies are now being 
conducted on the textural changes of treatments which improve firmness of French 
f r ie s . 



ADVERTISING OF FRESH & PROCESSED POTATOES BY FOOD STORES 

John H. Weber 
University of Idaho, Moscow 

My purpose is to present data on how important potatoes are in food retailing. 
The data come from an experiment in marketing research to determine whether 
analysis of food store advertising can serve better than other techniques to reveal 
trends. The premise is, of course, that the advertising that food stores put behind 
a product is an indication, and a good one, of how managers feel about the product, 
how important they feel it is in bringing customers into their stores. A comparison 
of advertising of one period with that of another will show changes in the minds of 
management on the importance of a product now and earlier. 

Potatoes were one of the products included in this experiment. Ten 
metropolitan areas were included, from east to west, north to south. The ten 
areas service about 25 percent of the nation's population. The main medium for 
food stores is the newspaper. Newspapers were read each day. Each food ad was 
cut out and the information coded on IBM cards. In this report the data cover the 
first 8 months of 1963, January through August. Some 6, 000 ads resulted in over 
40, 000 IBM cards. We do not have a long-enough period for a study of changes, but 
we do have enough sample to tell us something about potatoes and their importance 
in retail advertising and promotion. 

First let's go over some general findings. Twenty-three percent of food 
store advertising space is used for headlines, signatures, and promotion of the 
store's services, not of food. Seventy- seven percent is devoted to items. How this 
space is used indicates how management considers each department or item as a means 
of increasing business. Food stores distribute their space among departments in 
the following manner: meats 30 percent, dry groceries 40, produce 12, fresh dairy 
3, frozen foods 6, nonfoods 5, and bakery 3 percent. 

Estimates of contribution of each department to gross volume of sales come 
from Progressive Grocer's "Foodtown" (1954) and "Colonial Stores" (1962) studies, 
available from Progressive Grocer , 161 Sixth Ave., New York, 10013. Meats, which 
average about 25 percent of food store gross volume of sales, receive 31 percent of 
advertising space. Thus meats are an item that will attract customers to a store; 
they are a good department to promote to get business. On the other hand, dry 



67 



groceries, which account for about 50 percent of gross dollar volume, receive pro- 
portionately less advertising (only 40 percent of the space) and can be considered 
less competitive than meats. Fresh dairy products contribute slightly more than 
5 percent of gross dollar volume but receive only 3 percent of advertising space, 
which indicates that they are not competitive items that attract business. Produce 
and frozen foods are more like meats. More advertising space is devoted to them 
than they contribute to gross dollar volume. Produce is about 11 percent of sales 
and receives about 12 percent of advertising space. Frozen foods are about 4 percent 
of sales and receive about 6 percent of advertising space. 

Potatoes are important in the advertising of food stores. They are promoted 
in two departments, fresh produce and frozen foods, which are advertised more than 
their contribution to gross dollar volume. They are the most heavily advertised 
product in both of these departments. They are also sold as dehydrated, canned 
and chipped potatoes in the "dry grocery" department, which is not advertised as 
heavily as the department contributes to gross dollar volume, and they are not im- 
portant in the advertising program of the dry grocery department. Let's look at 
the individual potato products: 

Fresh potatoes. Fresh potatoes account for 25 percent of the tonnage and 
12 percent of the dollar volume in produce in food stores, or about 1 percent of total 
store sales. This importance is reflected in food store advertising; 25 percent of 
all ads in the study included fresh potatoes. No other item was advertised as much. 
Potatoes are also a main feature more than any other produce item. In the 6, 000 
ads in this study potatoes were a main feature 900 times or in 15 percent of all ads. 
The next most popular item was bananas, a main feature 600 times, or only 2/3 as 
often as potatoes. In descending order of importance come: watermelon, a main 
feature 500 times, cantaloupe 400, lettuce 400, tomatoes 300, apples 200, and 
oranges a main feature 200 times. This order might change if the four fall months 
were included; apples and oranges, for example, may receive more emphasis in the 
fall and come up to or pass watermelon and cantaloupe in number of times adver- 
tised. 

Not only are potatoes in 25 percent of food store ads, and a main feature in 
15 percent, but they are the ONLY produce feature item in 10 percent of the ads, or 
595 times out of 6, 000. K a grade is mentioned, 95 percent of the times it is U. S. 
No. 1 and the grade is mentioned about 70 percent of the times. Red potatoes are 
the most-often-advertised type, being advertised 45 percent of the time; 25 percent 
of the potatoes advertised are "russet" and about 25 percent are "white." About 
70 percent of the times they are advertised as 10-pound units, but also in 1, 3, 5, 8, 
15, 20, 25, 50, and 100 pound units. 

The state or origin of the potatoes is included in about 30 percent of the ads. 
In 40 percent of the cases the state is Idaho, in 38 percent California. Apparently 
store operators feel that Idaho and California have considerable sales appeal. Fresh 
potatoes are easily the single most important fresh produce item, and they receive 
a tremendous amount of advertising promotion from food stores. 

Frozen potatoes. Potatoes are the most popular frozen food, accounting for 
0.17 percent of store sales; peas are the next, accounting for 0.10 percent. 
( Progressive Grocer "Colonial Store" study. ) They are important in the advertising 



68 



of stores; 15 percent of all food store ads include frozen potatoes. They are a feature 
of the ad only about 15 percent of the times they appear, or in about 2 percent of the 
ads, as compared to 15 percent for fresh potatoes. While they are not advertised 
as much as fresh potatoes, they are a considerable factor in the advertising program 
of stores and are probably the most-featured frozen item. 

French fries or crinkle cuts are the most advertised frozen product; they 
were advertised 65 percent of the times frozen potatoes were advertised. Tiny 
taters, tots, or puffs were advertised 9 percent of the time; hash browns or cottage 
fries 16 percent of the time; and patties, whole potatoes, shoe string potatoes, 
stuffed potatoes and "assorted potato products" the other 10 percent. In advertising 
of frozen potatoes a most signficant factor is that 99 brands were mentioned often 
enough to show up statistically. 

Food stores put more emphasis on advertising potato specialty brands than 
they did on full-line national brands of frozen foods. An arbitrary decision was 
made here. Brands were divided into four different groups. One was the full-line 
national brands, such as Birdseye, Stokeley, Pictsweet and brands such as this 
which include a full line of frozen foods. The second category was brands of frozen 
potatoes in which only potato products were available, such as Valsing, Ore-Ida, 
and Rus-ettes. The third differentiation was that of retailer -owned private labels, 
such as A & P, Bel Air, Hillman' s ,IGA, etc. The fourth category was any brand 
that didn't fit into the other three. The four potato specialty national brands 
accounted for 24 percent of all advertising of frozen potatoes. The 9 full-line 
national brands of frozen products accounted for only 21 percent of all advertising 
of frozen potato products with one brand accounting for nearly half of mentions In 
this group. The 16 private retailer labels accounted for about 15 percent of all 
advertising of frozen potato products and the other 71 brands accounted for only 
40 percent of the advertising. The most often advertised brand was a specialty 
brand, which accounted for nearly 20 percent of all frozen potato advertising. The 
second most-often-advertised brand was a full-line national brand, which accounted 
for about 10 percent of all advertising. These two together accounted for about 30 
percent of all advertising of the 99 brands. 

The average advertised price per ounce was computed for the four categories. 
The full-line national brands were, on the average, 1. 77^ per ounce. The retailer- 
owned private lables were next highest at 1.43^ per ounce. The potato specialty 
brands, which were most often advertised, werel. 25^^; and the 71 other brands were 
the lowest at 1. 11^^ per ounce. These average prices were weighted for the number 
of times each brand appeared. 

It can be concluded that frozen potatoes are important in food store promo- 
tion and the better known full-line national brands do not receive the most promotion. 
The newer specialty brands receive the most promotion from food stores. Further, 
these specialty brands sell for significantly less than the full-line national brands or 
the retailer-owned brands. 

In terms of area in which frozen potatoes were promoted, San Frajicisco, 
New York, and Kansas City accounted for 57 percent of the advertising of frozen 
products; Chicago, Denver, and Dallas accounted for considerably less than average. 



69 



Dehydrated potatoes. Dehydrated potato products are not very important, it 
would seem, from the advertising standpoint, as they appear in only about 5 percent 
of food ads. They are a featured item less than 1 percent of the time. In 55 per- 
cent of the cases where dehydrated potatoes were advertised the word "instant" was 
used. "Granules" appeared only once. "Flakes" was used as a descriptive word 
only 6 percent of the time. In the minds of advertisers the word "instant" must 
have an appeal that other descriptive words used in the trade do not have. 

A significant factor with dehydrated potato products is that, as compared 
with 99 brands of frozen products, only 6 brands of dehydrated potatoes were 
advertised often enough to be significant. The most advertised brand was advertised 
23 percent of the times; the next, 19; the next 17. Here again, as in frozen products, 
potato specialty brands, such as Ore-Ida, and Idahoan, were promoted as much or 
more by food stores as the full-food-line national brands, such as Betty Crocker and 
Pillsbury. These new entries--new as compared to General Mills or General Foods-- 
have been able to hack out a significant market share by specializing in potatoes. 

The average advertised price for all dehydrated potato products was 3. 5^^ per 
ounce. Dehydrated potato products are advertised more -than- aver age in San 

Francisco, Minneapolis, and Kansas City and less than average in Los Angeles, 

Dallas, and Denver, 



RADIATION SPROUT INHIBITION OF POTATOES 

Fred Heiligman 
U. S. Army Natick Laboratories, Natick, Massachusetts 

A regulation, effective June 30, 1964, has been issued by the U. S, Food and 
Drug Administration allowing the use of ionizing radiation for the control of sprouting 

in potatoes. This regulation, published in the Federal Register, July 8, 1964 (page 
93Z9), extends the use of gamma radiation from cobalt-60 for the treatment of 
certain foods to include white potatoes, and permits the use of 5, 000 to 10, 000 rads 
(absorbed energy) to inhibit sprout development. 

From time to time, reports on the research and the progress being made on 
development of a process to utilize radiation energy for sprout inhibition have been 
presented to this conference (1, 2, 3), andhave appeared in the literature (4, 5, 6, 7, 8). 
A presentation of those data at this time would be superfluous as they were included 
in the Army's petition to the U. S. Food and Drug Administration and served as the 
basis for approval of use of the process. It may be of interest, however, to present 
a few of the more important factors that were considered in preparing the petition. 

Irradiation, in the approved dose range of 5, 000 to 10, 000 rads, is an ef- 
fective sprout inhibitor. The treatment causes little change, except for sprout 
inhibition, in the physiology of the tubers and does not significantly affect nutri- 
tional whole someness or culinary qualities. 



70 



A very successful pilot scale irradiation program was conducted in Canada 
in 1961-1962(9), which involved 787, 000 lbs. of potatoes and was done for the following 
reasons: (1) To provide an opportunity for the potato industry to use the irradiation 
method of sprout control and to evaluate its merits at first hand in terms of their 
own operations. (Z) To provide technical data on the handling and storage of potatoes 
irradiated on site under actual commercial operating conditions. (3) To provide 
information on the relative effectiveness of radiation and other methods of sprout 
inhibition being applied commercially by the potato industry. (4) To provide tech- 
nical and economic data regarding the design, construction, and operation of pilot- 
plant irradiation facilities which would be valuable in the design of full scale 
commercial facilities. (5) To determine public reaction to and acceptability of the 
first irradiated food offered for sale in Canada. 

The potatoes were irradiated at an average dose of 8, 000 rads in a trailer- 
mounted mobile irradiator. The test included six varieties (Kennebec, Sebaga, 
Katahdin, Netted Gem, Cherokee, and Irish Cobbler) and involved four types of 
storage conditions (pallet or tote box, bulk in bin storage, barrel storage, and bag 
storage). After irradiation, which extended from October 1961 through February 
196Z, the tubers were stored in 26 different storage centers. Potatoes in 8 of the 
26 centers were stored at controlled temperatures for the processing market, and 
those in the remaining 18 were stored under common conditions for the table stock 
market. 

The program was a complete success as far as control of sprouting was 
concerned. A dose of 8, 000 rads was completely effective in all trials regardless 
of variety, storage temperature, date of irradiation, and method and length of 
storage. In some storages it was possible to compare the effectiveness of radiation 
with that of various chemical inhibitors. In all cases, where these comparisons 
were made, irradiation proved to be the most potent sprout inhibitor. 

There has been much discussion concerning the effect of radiation on decay 
during storage. The Canadian study, and those conducted elsewhere (4, 7, 8) have 
shown that doses in the approved range (5, 000 to 10, 000 rads), and up to 15, 000 rads, 
does not significantly affect storage decay. When good materials suitable for long- 
term storage are irradiated and not mishandled during the treatment, irradiation in 
the sprout- inhibition dose range will not affect the rate of breakdown during storage. 

In the Canadian study the irradiated potatoes in the form of table stock or as 
processed products were sold to individual home consumers, hospitals, restaurants, 
and hotels. No complaints of any kind concerning the acceptability of the irradiated 
potatoes were received or reported. The irradiation did not have any significant 
effect on the chipping properties of the potatoes. It is also interesting that there 
was no unfavorable public reaction to the first irradiated food offered for sale in 
Canada. 

The results of experimentation done in the United States, Canada, and 
Europe have created a favorable climate for the future of potato irradiation. Now 
that it is lawful to market irradiated potatoes and products made from irradiated 
potatoes in the United States as well as in Canada, U. S. S. R. and other countries, we 
feel reasonably sure there will be a demand for the use of the process and that 
irradiation facilities will become available that will make the process economically 
feasible and profitable. 

71 



Literature cited 



1. Brownell, L.. E. , Burns, C. H. , Gustafson, F. G. , Islieb, D, , and Hooker, 
W. J. Storage Properties of Gamma Irradiated Potatoes. Proceedings, 
Seventh National Potato Utilization Conference, University of Maine, Orono, 
Maine (1956). 

2. Sawyer, R. L. Effects of Irradiation on Potatoes for Processing. Proceedings, 
Seventh National Potato Utilization Conference, University of Maine, Orono, 
Maine (1956). 

3. Heiligman, F. Irradiation of Potatoes, Eight National Potato Utilization Con- 
ference, Western Utilization Research and Development Division, U. S. D. A. , 
Albany, California (1957), 

4. Workman, M. , Patterson, M. E, , Ellis, N. K. , and He iligman, F. The 
Utilization of Ionizing Radiation to Increase the Storage Life of White Potatoes. 
Food Technology 14, 395 (1960). 

5. Heiligman, F. Effects of Ionizing Radiation on White Potatoes, American 
Potato Journal, 34, 156 (1957). 

6. Brownell, L. E., Gustafson, F. G. , Nehemias, J. R. , Islieb, D. R. , and 
Hooker, W. J. Storage Properties of Gamma Irradiated Tubers, Food 
Technology 11, 309 (1957). 

7. Duncan, D. T., Hooker, W. J. , and Heiligman, F. Storage Rot Sus ceptability 
of Potato Tubers Exposed to Minimum Inhibiting Levels of Ionizing Radiation. 
Food Technology 13, 159 (1959). 

8. Schrieber, J. L. , and Highlands, M. E. A Study of the Biochemistry of 
Irradiated Tubers Stored Under Commercial Conditions. Food Research 23, 
466 (1958). 

9. Report of the Results of the Canadian Pilot Scale Potato Irradiation Program, 
I96I-I962 Season. Atomic Energy of Canada, Limited, Ottawa, Canada. 



72 



ACCOMPLISHMENTS OF POTATO RESEARCH IN WASHINGTON 
Prepared by Institute of Agricultural Sciences, Washington State University 

Blackspot: Robert Kunkel and Cooperators 

The Washington Station was the first to publish results showing that blackspot 
is a reversible condition and that it is in some way associated with the turgor pressure 
of cells within the tuber. Later studies have shown that merely keeping the soil moist 
at all times is not sufficient to provide immunity. Hot days, root diseases, dry soil, 
exposure of harvested tubers to drying conditions, insufficient potash in the plant, 
rough handling, and cold temperatures all can contribute to making potatoes suscepti- 
ble to blackspot. 

Potash deficiency. Relatively large potash-deficient areas have been found in 
the Columbia Basin of Washington, and yield responses to potash have been obtained 
near the Zillah area. Deficiency sometimes occurs on spots in the field and some- 
times larger areas. In some spots applications of K^O as high as Z50 pounds per 
acre have not been sufficient to correct the deficiency. Potatoes harvested from 
potash-deficient areas are usually well netted, have a very high specific gravity and 
are extremely sensitive to blackspot when bruised, even if the soil has not been 
allowed to dry. In some cases the addition of adequate potash has reduced blackspot 
index by as much as 42 percent. 

Fertilizers. Very extensive studies using sources and levels of nitrogen, of 
phosphorus, and of potash have been made during the past six years. The effects on 
yield, grade specific gravity, potato chip color and blackspot susceptibility have been 
determined. It has been concluded that no one general fertilizer will be the best for 
all conditions of soil and culture existing in the Columbia Basin. On virgin soils, 
applications of nitrogen as high as 400 pounds per acre have given economic increases 
in yield if adequate phosphorus and potash are also available. Phosphorus is ac- 
cumulating in the soil and potash is disappearing faster than was formerly believed 
possible. High rates of nitrogen, phosphorus, and potash are not necessarily 
detrimental to yield, grade, specific gravity, and netting of Russet Burbank potatoes. 

Chips and fries. Potato chip studies and, to a more limited extent, frozen 
French fry studies have been made with potatoes from some of the fertilizer experi- 
ments. Generally the location in the experiment from which the samples were taken 
had a greater effect on the quality of the product than the fertilizer treatments applied. 

Varieties. Potato varieties (both named and unnamed) have been collected 
from breeders throughout the United States and tested during the past four years. 
Approximately a hundred have been tested for yield, grade, specific gravity, black- 
spot and chipping characteristics. Some white varieties have been high yielders and 
good chippers. They have not been pushed because they would be in competition with 
white varieties grown much closer to market. They would soon lose their identity on 
the fresh market and fail to demand the premium necessary to pay for the extra 
freight. Varieties which are exceptionally high yielding and have an exceptionally 
high dry matter content would be valuable for local processing regardless of shape 
or color. 



73 



Soil fumigation. Soil fumigation studies have been conducted for about five 
years. At first the objective was to determine whether or not a root condition was 
making the tubers susceptible to blackspot. Yield increases of about 200 cwt. per 
acre were obtained with the first crop after fumigation. A residual effect worth 
almost 100 cwt. per acre was obtained the second season. The better treatments 
would cost about $80. 00 per acre and they reduced the blackspot index about 30 per- 
cent under that obtained from the untreated checks. Fall fumigation is very effective 
and can be used when potatoes are to be planted in late March and April. 

Carbon dioxide. California's carbon dioxide theory for the prevention of black- 
spot has been tested for two years by several methods and found to be ineffective 
on Russet Burbank. Potatoes tested immediately after digging had about the same 
susceptibility to blackspot as after a waiting period of about seven hours, and were 
more susceptible to blackspot after a waiting period of Z4 hours. 



Potato Diseases : W. G. Hoyman 

Leaf roll . The potato leafroll disease has cost Washington potato growers 
many millions of dollars. It has been the most serious disease in the State for 
many years. The losses continue to occur each year and quite severely in some 
years. In 1959, for example, yield in central Washington was reduced about 50 
percent and loss was estimated at between 3 and 4 million dollars. In each case 
where current season infection is seen, it is possible to find chronic leafroll plants. 
"Chronic" is the term given to seed tubers infected with the virus. In other words, 
the virus is present in the seed. 

In some areas it may be possible to apply insecticides and reduce losses 
caused by insect- transmitted viruses. The situation in Washington is somewhat 
different from conditions in most other potato-growing areas. Enormous numbers 
of the green peach aphid are sometimes present in central Washington potato fields. 
Even though they can be partially controlled by certain insecticides, it has been 
impossible to stop the spread of leafroll. The most logical and practical method is 
to purchase seed free of the virus. Growers have indicated they are doing so but 
still the virus is present to a certain extent in some seed lots. 

A visit to Montana seed areas alerted growers to the fact that they did have 
a small amount of leafroll in some seed lots. Some Montana growers have had a 
slight amount of leafroll in their seed stocks for many years. This was true even 
though the Montana certified seed lists did not mention leafroll previous to 1959. 
Some infected tubers have thereby been shipped into Washington each year and this 
has been a source of inoculum for our current season infection. Because Washington 
growers purchase much seed from Montana, the Washington State Potato Commission 
has requested Dr. Hoyman to visit the Montana seed areas each summer. During 
the last few years considerable potato storage has been constructed in the Columbia 
Basin. This is necessary for our processing industry and it also provides an 
opportunity for the grower to spread his marketing season over a few months. K 
Washington potato growers had the severe leafroll problem that occurred in some 
previous years, there would be no processing industry and thereby no need for 
storage. 



74 



As a result of this preliminary work improving the available seed for Wash- 
ington growers, a seed evaluation trial was started in 1961. With the cooperation of 
the State Department of Agriculture, the horticultural inspectors sample each lot 
of seed being planted in Washington. Three hundred small tubers are removed from 
each seed lot and planted at the Othello Research Farm. Leafroll and ringrot 
readings are taken during the growing season. In 1961, 43 percent of the seed lots 
entered had chronic leafroll. The amount dropped to 27 percent in 1962 and to 19 per- 
cent in 1963. These figures indicate a gradual improvement. 

Ringrot. Each year since 195 8, ringrot has been found in a few seed lots. 
The Extension potato specialist, Nick Sandar, has been responsible for finding most 
of the infected lots. In most instances, the infection was found before any potatoes 
were planted. This service has saved some growers thousands of dollars and it 
has also helped the seed certification agencies in some states. In the high- altitude 
seed areas where the growing season is not too long, it is sometimes impossible to 
find ringrot symptoms in the field even though some plants may be infected. Finding 
the infected seed lots during seed cutting operations in Washington has made it 
possible for the certifying agencies to eliminate the infected lots for further certifi- 
cation. 

Seed treatment. About 5 years ago it was not uncommon to find many 
potato fields with poor stands. An investigation indicated the cause was generally 
due to Fusarium seed piece decay. Seed treatment experiments were conducted at 
various places in central Washington to determine whether this decay could be 
prevented. Captan was found to be one of the best materials. The dust form has 
been recommended provided the grower applies it satisfactorily. The wet treatment 
gives satisfactory protection too but the usual dip treatment has not been recom- 
mended. If ringrot tubers are present in the seed, dipping the cut seed will generally 
increase the amount of infection. This has happened in the Columbia Basin with the 
result that the grower experienced a severe financial loss. If a wet treatment is 
used, the fungicide should be sprayed on the cut seed as it travels over a conveyor 
belt. 

Rhizoctonia. Experiments the past 3 years have indicated the best means of 
reducing the losses from stem infection of Rhizoctonia is to provide cultural con- 
ditions for rapid emergence of the plants. Dormancy should be broken and seed 
piece size is very important. Seed pieces should not weigh less than 1. 5 ounces. 

Verticillium wilt resistance. This disease is severe in the Yakima Valley 
and is becoming rriore acute in the Columbia Basin. It is also present at EUensburg. 
There seems to be no practical method of control at present except the planting of 
resistant varieties. Long crop rotations will help. The breeding program at the 
Irrigation Experiment Station has shown that it is possible to obtain resistant 
varieties. Several new resistant selections are being tested as possible varieties. 
One of the new selections looks very promising for processing. It is resistant to 
Verticillium wilt, common scab, leafroll and virus X. In the short time it has been 
tested, it has yielded well on soil that is heavily infested with the wilt organism. 
In 1963 it yielded at the rate of 35 tons per acre on land that has had potatoes for 
6 continuous years. Processors will like this new potato because it can be processed 
directly from cold storage. This is a rare quality in a potato and one that will save 
processors thousands of dollars. It is being increased as rapidly as possible by 



75 



Washington seed growers. 

Leaf roll resistance. One of the objectives of the breeding program is to 
develop one or more new varieties that are resistant to leafroll. Of special im- 
portance is to have new varieties that do not develop net necrosis in the tubers. 
The results to date have shown it is not difficult to obtain resistance to the net 
necrosis phase of this disease. Resistance to net necrosis will alleviate the problem 
now encountered in some potatoes being stored for processing or the fresh market. 

Seed potato production. A few new selections have been developed at the 
Irrigation Experiment Station that are very resistant to Verticillium and leafroll. 
Seed has been raised at Prosser. Within not too many years it may be possible to 
grow seed in some areas of central Washington. This would save the growers the 
expense of purchasing seed each year and thereby lower the production costs, 
enabling growers to meet the severe competition from other potato-growing areas. 



Potato Handling and Shipping Studies: Merle Weaver 

Investigations during the first two years were directed by Dr. Fenton E. 
Larsen. During this period, the techniques for the evaluation of internal and ex- 
ternal tuber injury were standardized. The potato industry of Washington was 
surveyed to determine the amount and degree of external and internal blackspot 
injury caused during harvest, during preparation for market, and during shipment. 
It was found that nearly 80 percent of the potatoes having external injury and internal 
blackspot injury were injured during harvest (digging, loading, and hauling to the 
shed). Grading and shipping nearly doubled the number of blackspots per sample, 
in addition to increasing the intensity of color per spot. Most improvements can be 
made by studying cultural and mechanical operations right in the state of Washington. 

Bulk potato shipping studies. The WSU bulk potato shipping study was the 
first to show that warm, immature, and wet tubers could be shipped loose in a 
specially designed bulk-potato car during warm weather. It was shown that mechanial 
methods of loading bulk-potato cars can be developed and used. It also showed that 
mechanical unloading at the receiving point was both efficient and labor saving. 
External and internal blackspot injury was less on tubers shipped in the WSU bulk- 
potato car than on tubers shipped in 100-pound burlap bags. Sacks were eliminated. 
Manpower requirements at both the shipping and receiving points could be reduced. 
Freight rates could be reduced due to the ability to ship larger loads (65, 000 pounds 
in the bulk-potato cars vs. 45, 000 pounds in the sack car). At least 175 specially 
built cars of this type are now being used by the Great Northern Railroad. Other 
railroads are investigating their needs. 

Water truck. Internal blackspot injury and external tuber injury (cuts, cracks, 
skins and bruises) incurred while tubers were being loaded into trucks could almost 
be eliminated by dropping tubers into water in a water tight truck bed. Intensity of 
color per spot was also reduced by harvesting into water. Water truck beds do not 
require chain conveyors or hoist trucks to remove the tubers. Water from flumes 
or holding tanks could be used to wash tubers out of the bed. The initial cost of 
water truck beds as well as maintenance costs would be reduced. 



76 



Hydrocooling studies. Pulp temperatures have been dropped or raised by 
10* in approximately one minute by using cold or warm water. The greater the 
differential between water and pulp temperature, the more rapidly will be the rate 
of change. Preliminary experiments have shown that cracks and hair cracks on 
tubers coming out of storage could be reduced by raising the pulp temperature 
prior to grading. 

High temperature studies. Tubers exposed to a temperature of 105° for 3 
hours will develop severe black heart conditions when shipped or put into storage. 
If tubers are injured during harvest, grading, or shipment after being exposed to 
temperatures of 105 "F for 3 hours, the injured areas will rapidly rot toward the 
center. It is felt that this was the cause of what was referred to during the 1961 
season as "the blackspot that rots to the center. " Once tubers have been exposed 
to temperatures of this magnitude and duration, whether during the time they were 
in the field, or while they were in the truck prior to unloading at the shed, or during 
shipment to market, no handling technique can prevent this rot from occurring. 
Respiration data suggests that the process occurring in the center of the tuber and 
in the injured areas were the same. Some rejected loads previously attributed to 
soft rot may actually be due to high temperature injury and methods of control must 
be different. 

Chemical analysis of blackspot. Determining whether blackspot susceptibility 
is purely chemical, physical, or a combination of both would be of Inestimable 
value in learning how to control this disorder. Analysis of susceptible and non- 
susceptible stem and tissue has not been consistent or conclusive in its relationship 
to carbohydrate content or amino acid content. 

Enzymes studies . The enzyme tyrosinase is believed to be responsible for 
converting the amino acid tyrosine to melanin. Melanin is the black color found in 
blackspot. A rapid colorimetric technique for evaluating tyrosinase activity has 
been developed. With this test many readily available enzyme inhibitors have been 
found. However, no method of getting these materials into the tuber has been 
devised, but methods are being studied. Copper was found to greatly increase 
tyrosinase activity, thereby increasing the possibility for melanin production. 
Copper is one of the trace elements often included in some commercial fertilizers, 
and as copper sulphate it is used to prevent the growth of algae in irrigation canals. 
Its relationship to blackspot under field conditions will have to be determined. 

Carbon dioxide. Analysis has shown that the carbon dioxide content in tuber 
tissue taken from wet and dry soil was approximately the same. Tubers on dry 
soil under Washington conditions have been shown to be most susceptible to black- 
spot. It was shown that the carbon dioxide content was highest in the blossom end 
of the tuber. The blossom end is the least susceptible part of the tuber. Analysis 
has also shown that the carbon dioxide content increased with time after harvest. 
Usually tubers are most susceptible to blackspot immediately after harvest. If 
there is a relationship between the carbon dioxide content and blackspot suscepti- 
bility, it is exactly the reverse of the relationship proposed in California. California 
associates the high carbon dioxide content in the soil with increased blackspot 
susceptibility. 



77 



Potato Insect Control: B. J. Landis 



USDA entomologists have worked on various eastern Washington potato 
insect problems since 1941 but only major accomplishments since the Washington 
State Potato Commission began assisting in the work will be reviewed here. 

D evelopment of con t rol measure s for phosphate -resistant gre en peach aphids. 
Starting in 195Z all insecticides that had previously controlled the aphid failed when 
applied with aircraft. Concurrently with the search for new insecticides that were 
effective when applied in this manner, the Washington strain of the aphid was studied 
for two years in the laboratory and found more resistant than aphids from the 
eastern part of the country to phosphate - type insecticides, such as parathion and 
malathion. We first tested the experimental insecticide endosulfan (Thiodan) in 
1956 with ground equipment but the full potential of this aphicide was not realized 
until experimental applications were made with aircraft in 1957. At various potato 
schools held during the winter of 1957-8 we reported that "Two years' tests with 
Thiodan have shown this insecticide to be much better than anything previously 
tested for control of aphids. " Endosulfan became available to growers in 1958 and 
has given excellent control since then with no evidence that they are developing a 
resistance to it. Washington was the first state to recommend it for control of 
aphids on potatoes. It is now widely recommended for control of aphids throughout 
the country. 

Assistanc e in est ablishment of a tolerance for D DT res idues in potatoes. 
About 15 years ago USDA entomologists at Walla Walla found that a single applica- 
tion of DDT to the soil controlled destructive wet-land wireworms for six or more 
years. DDT was recormnended for control of wireworms on potatoes in the West 
from 1951 until about 1958 when federal legislation caused USDA entomologists to 
withdraw their recommendation until a realistic residue tolerance had been estab- 
lished. There was a reluctance on the part of anyone to prepare a petition for a 
tolerance for DDT but because of the urgent need for a greater choice of effective 
insecticides for wireworm control we were able to interest various state, federal 
and grower organizations and the insecticide industry in our problem. The largest 
manufacturer of DDT then assembled residue data that had been accumulated by 
federal and state workers and after a hearing at Washington, D. C. , the Federal 
Register announced on October Z2, I960 that a tolerance of 1 p. p. m. DDT had been 
established in washed potatoes. Although several carloads were seized by the Food 
and Drug Administration in the fall of 1962 because of overtole ranee residues of 
other soil insecticides the 1 p. p. m. tolerance established in I960 for DDT appeared 
ample and no potatoes were seized because of its use. DDT is still one of the most 
effective available insecticides for control of wireworms in the West. 

Non^-^ r s istent, q uick-killing subs titute s for aldrin usefu l for contro l 
of wireworms. Growers had applied aldrin in various ways to the soil for a number 
of years before 1962 for wireworm control without trouble with illegal residues. 
Following Food and Drug Administration seizures of some potatoes moving in inter- 
state commerce because of overtolerance amounts of combined aldrin and dieldrin 
(aldrin converts to dieldrin in the soil) our growers and the manufacturers of these 
insecticides were at a loss to account for the sudden appearance of an abnormal 
residue problem. Using soil insecticide plots in the Columbia Basin and Yakima 
Valley in which we had applied aldrin at the registered dosage and in the recommende 



78 



way in the spring of 1962 as a base, cooperating USDA chemists found that under 
certain conditions ove rtole ranee levels of aldrin-dieldrin are now detectable in 
samples analyzed by gas chromatography. Cancellation of federal registration of 
aldrin for potatoes was based largely on results of experimental work at the Yakima 
laboratory in 1962. 

Anticipating a vacuum left by the nonavailability of aldrin for wireworm 
control Dr. J. A. Onsager of this laboratory and B. J. Landis initiated large field 
experiments near George, Washington, in the spring of 1963 in which many chemical 
compounds that had already been registered for use on potatoes, and had shown 
promise for control of related wireworms in other parts of the country, were tested. 
As the result, the Washington State University plans to recommend for the 1964 
season the use of four insecticides for control of wireworms, of which parathion and 
diazinon are new here and were the most effective materials we tested in 1963. Both 
of these insecticides kill wireworms quickly and may be applied shortly before 
planting, if desired. 

Di-Syston soil placement and timing studies for aphid control. Di-Syston 
gave longest systemic control of aphids during 13 years' study of available systemic 
insecticides tested on potatoes. However, in Washington Di-Syston soil treatments 
effectively controlled aphids for only 40 to 60 days, or less than in other parts of 
the country. Because potatoes require 100 to 120 or more days of growth and the 
heavy aphid flight takes place between June 15 and August 1 experiments on timing 
and placement were required. Results showed it was best to delay soil treatment 
on very early plantings and side- dress these fields with granules during the period 
Ivlay 15 to ZO. This extended the effectiveness of the Di-Syston treatment into the 
bad aphid period of July. Banding Di-Syston in the soil at planting time for crops 
planted from May 15 to the end of the planting period was also found effective. During 
summers when aphids were not killed by heat in August supplemental foliage treat- 
ments with endosulfan were found necessary. 

Effective control of apnid s with insec ticides reduced spread of leafroll and 
de velopr nent of ne t n ecrosi s. Studies conducted in eastern Washington for a number 
of years have shown that a minimum of three insecticidal treatments to potato 
foliage applied as recommended in Washington State University Handbook on Insects 
not only reduces direct feeding loss from the green peach aphid but under favorable 
conditions reduces losses from leafroll. Favorable conditions are defined as a 
desire on the part of a group of potato growers in a district to eliminate the usual 
sources of leafroll by eradication of volunteer potato plants and the choice of good 
seed followed by the suppression of green peach aphid populations to manageable 
levels by means of a planned, tested insecticide program. One application per 
season mads to potato foliage after aphids become well established is of dubious 
value for prevention of disease spread by aphids. Measurable reduction in losses 
from aphid-borne disease was first obtained in our experimental plots in 1949 and 
as late as 1962. Prevention of losses from leafroll is difficult but not impracticable, 
provided there is the will to try. 



79 



Potato Problems that Need Further Research 



1. Even though much has been learned about susceptibility of tubers to black- 
spot, much needs to be learned about use of information under field conditions. 
Exploratory work has been started. Tests with vine killers of all kinds, tuber 
weighings and foliage depressants have been tried in an effort to gain information 
basic to experiments in the future. 

Z. Fertilizer studies will be a major problem in the Columbia Basin until 
irrigated agriculture has stabilized the soils. Soils recently brought under irrigation 
change rapidly in organic matter, physical condition, and chemistry. For some time 
there will be large differences in fertilizer requirements caused by differences in 
cropping practices. The indiscriminate use of minor elements, especially boron and 
copper, can lead to difficulties later. 

3. Studies on keeping quality of overmature potatoes during warm weather 
may stabilize market prices between September 15 and October 31 in the Basin. 

4. Soil fumigation is in its infancy as to available materials and crops on 
which it might be beneficial. 

5. Much is still to be learned about the judicious use of irrigation water and 
the subsequent effect on yields and quality. 

6. Investigate the effects of warming tubers on the incidence of cracks, 
hairchecks, and bruises. 

7. Continue work on high temperature injury, especially in determining ways 
of preventing high soil temperatures prior to harvest. 

8. Continue studies on reduction of blackspot by undercutting techniques. 

9. Expand enzyme studies with special reference to enzyme inhibitors and 
msans of getting them into tubers. Isolate and identify enzyme substrates that are 
capable of producing black color in tubers. Investigate other respiratory and oxida- 
tive enzymes and their possible relationship to color production. 

10. Determine the relationship of respiration rate to blackspot and blackheart. 
Continue studies on effect of the carbon dioxide in the tuber on blackspot susceptibility. 

11. Determine the causes and develop means of prevention of internal tuber 
breakdown (soft rot, blackheart) which occurs in storage and in transit. 

IZ. Study specific chemical constituents of tubers, known to be associated with 
color production. 

13. Cooperate with the other members of the research staff supported by the 
Potato Commission on problems for which this project has the equipment to assist. 
New equipment, including thin-layer chromatography and gas chromatography, should 
offer new avenues of approach to problems. 

14. Develop a longer lasting, s ingle - application treatment with a systemic 
insecticide for control of aphids and other pests. 

15. Further perfection of wireworm control treatments with nonpe r s istent 
insecticides that do not leave objectionable residues in potatoes. 

16. Develop more effective control of the two-spotted spider mite. 

17. Develop a seed treatment for prevention of stand losses caused by seed- 
corn maggot. 

18. Develop insecticidal control measures for white grubs (old but satisfactory 
treatments are no longer usable because of residue problems). 



80 



ATTENDANCE 



Sorney Foods 
Kingslynn, England 

Mark T. Buchanan 
Washington State University 
Pullman, Washington 

John C. Campbell 
Rutgers University 
New Brunswick, N, J. 

Virgil Campbell 
Fred Meyer, Inc. 
Portland, Oregon 

Roy Carlson 
Wash. State Dept. 

of Agriculture 
Olympia, Washington 

Charles H. Carpenter 
Fourdrinier Kraft Board 

Institute, Inc. 
New York, N. Y. 



Kenneth J. Crow 
Public Utility District 

of Grant County 
Ephrata, Washington 

L. P. Croxton 
Yakima, Washington 

C. E. Cunningham 
Campbell Soup Company 
Riverton, N. J. 

Helen H. Cunningham 
University of Idaho 
Moscow, Idaho 

David Curran 
Fibreboard Paper 

Products Corporation 
Antioch, California 

Lyle W. Currie 

Red River Valley Potato 

Growers Association 
East Grand Forks, Minn. 

Glenn Danielson 
Nalley's Inc. 
Tacoma, Washington 



William B. Ackley 
Washington State University 
Pullman, Washington 

R. V. Akeley 

Agricultural Research Service 
Beltsville, Maryland 

Bill Bagby 
SPUDMAN Magazine 
Tulelake, California 

John T. Baillargeon 
Coates Electric Mfg. Co. 
Seattle, Washington 

Don Bakes 

Washington State University 
Prosser, Washington 

John A. Barnes 

The Pills bury Company 

Minneapolis, Minn. 

William L. Beale 
Frito-Lay Inc. 
Madison, Wisconsin 

Kris P. Bemis 
United Fresh Fruit & 

Vegetable Assoc. 
Washington, D. C. 

Gerald S. Birth 

Agricultural Marketing Service 
Beltsville, Maryland 

Hoyt A. Blackstock 
Carnation Company 
Van Nuys, California 

Roy Bosley 

J. R. Simplot Co. 

Caldwell, Idaho 

Mr.&Mrs. C. E. Botkin 
Claude Botkin Co. , Inc. 
Arvin, California 

Frank P. Boyle 

Western Regional Research 

Laboratory, USDA 
Albany, California 



Errol Brown 

Brown & Kelly Produce, Inc. 
Quincy, Washington 

G. A. Brown 



Don L. Cazier 

The R. T. French Co. 

Shelley, Idaho 

Sam Churchill 
Farm Editor 
Yakima Herald 
Yakima, Washington 

Kenneth L. Cook 
N. P. Railway Co, 
Seattle, Washington 

M. J. Copley 

Western Regional Research 

Laboratory, USDA 
Albany, California 

James Cording 

Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pa, 

Dan Crawford 
SPUDMAN Magazine 
Tulelake, California 



Joffre C. David 

Florida Fruit & Vegetable Assoc. 
Orlando, Florida 



Boynton Dodge 

Wash. State Potato Commission 
Quincy, Washington 



Joseph D. Dwyer 

Wash. State Dept. of Agriculture 

Olympia, Washington 



Govert A. Dyke 

The Milwaukee Road 

Spokane, Washington 



J. A. Davidson 
McCain Foods Ltd. 
Florenceville, N. B. , Canada 

C. O. Davis 
Cornell University 
Ithaca, New York 



Gerry Dodge 
Ellensburg, Wisconsin 



81 



Paul J. Eastman 

Maine Dept. of Agriculture 

Augusta, Maine 

LaVerne Ellefson 
Borden Foods Company 
Grafton, North Dakota 

William J, Englar 
Rogers Brothers Company 
Idaho Falls, Idaho 

Roderick K. Eskew 
Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pa. 

Bernard Feinberg 

Western Regional Research 

Laboratory, USDA 
Albany, California 

Irvin C. Feustel 
Federal Extension 

Service, USDA 
Albany, California 

T. J. Fitzpatrick 

Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pa. 

W. L. Gardner 
Lovins Produce, Inc. 
Moses Lake, Washington 

D. L. Gibson 
Fresh-Pak Limited 
Burnaby, B. C. , Canada 

J. K. Greig 

Kansas State University 
Manhattan, Kansas 

Sven Grufstedt 
A. B. Culinar 
Sweden 

Paul Hackstadt 
Nalley's, Inc. 
Tacoma, Washington 

Sam Haddad 
Ore-Ida Foods, Inc. 
Ontario, Oregon 



Ron Haile 

J. R. Simplot Company 
Caldwell, Idaho 

A. E. Harstad 

Pennsalt Chemicals Corp. 

Tacoma, Washington 

F. H. Hatfield 
Hatfield Industries Ltd. 
Hartland, N. B. , Canada 

Mrs, F. H. Hatfield 
Canadian Potato Chip Assoc. 
Hartland, N. B. , Canada 

Arthur Hawkins 
University of Connecticut 
Storrs, Connecticut 

Fred Heiligman 

U. S. Army Natick Lab. 

Natick, Mass. 

Peter S. Helming 
Ore-Ida Foods Inc. 
Burley, Idaho 

Mr. &Mrs. R. Hendrick 
Phil A. Livesley Co. 
Portland, Oregon 

Allan E, Henry 
Agricultural Marketing 

Service, USDA 
Portland, Oregon 

Larry Hilaire 

Hilaire's Encore Restaurant 
Portland, Oregon 

Ernest J. Holcomb 
Agricultural Marketing Serv. 
Washington, D. C. 

F. D. Howard 
University of California 
Davis, California 

Nelson Howard 
Lamb-Weston, Inc. 
American Falls, Idaho 

W. G. Hoyman 
Agricultural Research Serv. 
Prosser, Washington 



Edward Humphrey 
State of Maine 
Augusta, Maine 

Alan Hunt 

Wash. State Dept. 

of Agriculture 
Olympia, Washington 

Frank W. Hussey 

U. S. Dept. of Agriculture 

Washington, D. C. 

W. M. Iritani 

Sunspiced Vegetables of Idaho 
Blackfoot, Idaho 

Charles E. Jarrett 
Great Northern Railway 
Seattle, Washington 

Jim Johnson 

Washington State University 
Pullman, Washington 

Sterling Johnson 

Idaho Potato Processors, Inc. 

Burley, Idaho 

Norman Johnston 
Emery Industries 
Santa Fe Spring, California 

E. Crawford Jones 
American Potato Company 
Blackfoot, Idaho 

Carlton Judkins 

Idaho Potato Growers, Inc. 

Idaho Falls, Idaho 

William L. Kannapel 
Pasco, Washington 

Errol H. Karr 

Pennsalt Chemicals Corp. 

Tacoma, Washington 

Ray D. Kearl 

U. S. Dept. of Agriculture 

Yakima, Washington 

John Keene 

Yakima County Extension Serv. 
Yakima, Washington 



82 



Percy A. Kelly 

Brown & Kelly Produce, Inc. 

Winchester, Washington 

Cecil E. Kent 
Western Idaho Potato 

Processing, Inc. 
Nampa, Idaho 

Richard L. Kerbs 
Russet Potato Company 
Blackfoot, Idaho 

Ron Kercheval 
Chef Reddy Foods 
Othello, Washington 

Ray Kern 

Wash. State Dept. 

of Agriculture 
Olympia, Washington 

John A. Kitson 
Canada Department 

of Agriculture 
Summerland, B. C. 

Ray W. Kueneman 
J. R. Simplot Co. 
Caldwell, Idaho 

Robert Kunkel 

Washington State University 

Pullman, Washington 

B. J. Landis 
Entomology Research 

Division, ARS 
Yakima, Washington 

W. Grant Lee 
Statistical Reporting 

Service, USDA 
Washington, D. C. 

Duane Le Tourneau 
University of Idaho 
Moscow, Idaho 

Mr. &Mrs. Phil Livesley 
Phil A. Livesley Co. 
Portland, Oregon 

O. R. Lovins 

Lovins Produce 

Moses Lake, Washington 



W, D. Maclay 

Agricultural Research Serv. 
Washington, D. C. 

Frank Manzer 
University of Maine 
Orono, Maine 

C. E. Mason 
Baker Machinery 

and Baker Produce 
Kennewick, Wisconsin 

DeanE. McCrory 
Pennsalt Chemicals Corp. 
Tacoma, Washington 

J. M. McCullough 
Pellsalt Chemicals Corp. 
Tacoma, Washington 

Robert McGee 

J. R. Simplot Company 

Caldwell, Idaho 

Richard McLaughlin 
Lamb-Weston, Inc. 
American Falls, Idaho 

Robert L. Mercer 

R. T. French Company 

Shelley, Idaho 

A. E. Mercker 
National Potato Council 
Washington, D. C. 

George A. Mick 
Yakima, Washington 

C. R. Miller 

Stokely Van Camp, Inc. 

Zillah, Washington 

Richard A. Miller 
Miller's Pre-Pared 

Potato Co. 
Blue Island, Illinois 

Sevart Miller 
Country Gardens Inc. 
Warden, Washington 

Gilbert H. Monroe 

Idaho Potato Growers, Inc. 

Idaho Falls, Idaho 

83 



Roy E. Morse 

Thomas J. Lipton, Inc. 

Englewood Cliffs, N. J. 

Paul N. Mosher 
University of Maine 
Orono, Maine 

H. H. Mottern 

National Dairy Products Corp. 
Glenview, Illinois 

Otis C. Moyer 

Basin Produce Co. , Inc. 

Moses Lake, Washington 

Hugh J. Murphy 
University of Maine 
Orono, Maine 

C. H. H. Neufeld 

Western Regional Research 

Laboratory, USDA 
Albany, California 

C. T. Nielsen 

Wash. State Dept. of Agriculture 
Moses Lake, Washington 

Robert E. Nylund 
University of Minnesota 
St. Paul, Minnesota 

Robert B. O'Keefe 
University of Nebraska 
Lincoln, Nebraska 

Robert E. Olson 

Western Regional Research 

Laboratory, USDA 
Albany, California 

C. A. Park 

Canada Dept. of Agriculture 
Ottawa, Ontario 

Alvah L. Perry 
University of Maine 
Orono, Maine 

Elmer C. Pifer 
Pennsylvania State University 
University Park, Pa, 

W, L. Porter 

Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pennsylvania 



Myron J. Powers 
Washington State University 
Pullnnan, Washington 

Russell T. Prescott 
Western Regional Research 

Laboratory, USDA 
Albany, California 

Joe Rainwater 
American Potato Co. 
Blackfoot, Idaho 

Fred Ramsey 
Wash. State 

Potato Commission 
Yakima, Washington 

Clyde Li. Rasmussen 
Western Regional Research 

Laboratory, USDA 
Albany, California 

Sid Reese 

Lamb- Weston, Inc. 
Portland, Oregon 

Donald B. Robertson 
J. R. Simplot Co. 
Heyburn, Idaho 

William F. Romney 
Romney Produce Co. 
El Paso, Texas 

Robert E. Rose 
Wash, State Dept. 

of Commerce 
Olympia, Washington 

Nick Sandar 

U. S. Dept. of Agriculture 
East Grand Forks, Minn. 

Lee Sandberg 
Statistical Reporting 

Service, USDA 
Seattle, Washington 

Richard L. Sawyer 
Cornell University 
Riverhead, N. Y. 

John A. Schoenemann 
University of Wisconsin 
Madison, Wisconsin 



Roy Shaw 

Red River Valley Potato 
Processing Laboratory 
East Grand Forks, Minn. 

Ir. P. H. Sijbring 
I, B, V. L. 

Wageninger, Nederland 

John D. Snow 
Potato Processors 

of Idaho Assoc. 
Burley, Idaho 

T. E. Snyder 
Campbell Soup Co. 
Riverton, New Jersey 

Larry V. Summers 
University of Idaho 
Moscow, Idaho 

Eugene- A. Talley 

Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pa, 

Russell H. Thackery 
Russel Thackery 

& Associates 
Columbus, Ohio 

Robert H. Treadway 
Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pa. 

Don E. Trimble 
State of Washington - 

Potato Committee 
Yakima, Washington 

Archie Van Doren 
Tectrol Division 
Whirlpool Corporation 
Wenatchee, Washington 

Art Van Fleet 
Yoshino- Western, Inc. 
Quincy, Washington 

K. E. Waud 

Washington State University 
Othello, Washington 

Merle L. Weaver 
Washington State University 
Pullman, Washington 
84 



Merrill R. Webb 

Ore -Calif, Potato Committee 

Redmond, Oregon 

John H. Weber 
University of Idaho 
Moscow, Idaho 

P, A. Wells 

Eastern Regional Research 

Laboratory, USDA 
Philadelphia, Pa. 

Bert G. Wilcox 
Oregon State University 
Klamath Falls, -Oregon 

George W, Woodbury 
University of Idaho 
Moscow, Idaho 

Milton Workman 
Colorado State University 
Fort Collins, Colorado 

Headlee Wright 

San Luis Valley Potato 

Administrative Committee 
Monte Vista, Colorado 

George Yoshino 
Yoshino- Western, Inc, 
Quincy, Washington 

Donald A. Young 

Canada Dept. of Agriculture 

Fredericton, N. B, 

Mary V. Zaehringer 

Idaho Agricultural Expt. Station 

University of Idaho 

Moscow, Idaho 

Ray Zielinski 

Idaho Potato Processors, Inc, 
Burley, Idaho 



GPO 973-055